## Database functions

DAVERAGE: returns the average of selected database entries.

DCOUNT: counts the cells that contain numbers in a database.

DCOUNTA: counts non-blank cells in a database.

DGET: extracts a single record that matches the specified criteria from a database.

DMAX: returns the maximum value from selected database entries.

DMIN: returns the minimum value from selected database entries.

DPRODUCT: multiplies the values in a field for records that match the specified criteria in a database.

DSTDEV: estimates the standard deviation based on a sample of selected database entries.

DSTDEVP: calculates the standard deviation based on the entire population of selected database entries.

DSUM: adds the numbers in a field for records that match the specified criteria in a database.

DVAR: estimates variance based on a sample of selected database entries.

DVARP: calculates variance based on the entire population of selected database entries.

GETPIVOTDATA: returns data stored in a pivot table.

## Date and time functions

DATE: returns a date.

DATEDIF: calculates the number of days, months, or years between two dates.

DATEVALUE: converts a date in text format to a serial number.

DAY: returns the day of a date. The day is given as an integer ranging from 1 to 31.

DAYS360: returns the number of days between two dates based on a 360-day year (twelve 30-day months), which is used in some accounting calculations. You can use this function to compute payments if your accounting system is based on twelve 30-day months.

EDATE: returns a date that is a specified number of months before or after the specified start date. You can use this function to calculate maturity dates or due dates that fall on the same day of a month as the date of issue.

EOMONTH: returns the last day of a month that is a specified number of months before or after the specified start date. You can use this function to calculate maturity dates or due dates that fall on the last day of a month.

HOUR: returns the hour of a time value. The hour is given as an integer ranging from 0 (12:00 A.M.) to 23 (11:00 P.M.) .

MINUTE: returns the minutes of a time value. The minute is given as an integer ranging from 0 to 59.

MONTH: returns the month of a date. The month is given as an integer ranging from 1 (January) to 12 (December).

NETWORKDAYS: returns the number of working days between the specified start date and end date. Working days exclude weekends and any specified holidays. You can use this function to calculate employee benefits that accrue based on the number of working days during a specific period.

NETWORKDAYS.INTL: returns the number of working days between two dates.

NOW: returns the current date and time. If the cell format is general before you enter this function, it changes to time for the result of this function.

SECOND: returns the seconds of a time value. The second is given as an integer ranging from 0 (zero) to 59.

TIME: returns the decimal for a time. If the cell format is general before you enter this function, it changes to time for the result of this function.

TIMEVALUE: returns the decimal of a time represented by a text string. The decimal is a value ranging from 0 (zero) to 0.999999999, which represents a time from 0:00:00 (12:00:00 A.M.) to 23:59:59 (11:59:59 P.M.) .

TODAY: returns the current date. If the cell format is general before you enter this function, it changes to date for the result of this function.

WEEKDAY: returns the day of the week corresponding to a date. The day is given as an integer ranging from 1 (Sunday) to 7 (Saturday) by default.

WEEKNUM: returns an integer that represents the week number of a specific date in a year.

WORKDAY: returns a date that is a specified number of working days before or after the specified start date. Working days exclude weekends and any specified holidays. You can use this function to exclude weekends or holidays when you calculate invoice due dates, expected delivery time, or the number of working days.

WORKDAY.INTL: returns a date before or after a specified number of working days, where weekends can be customized.

YEAR: returns the year corresponding to a date. The year is returned as an integer ranging from 1900 to 9999.

YEARFRAC: calculates the fraction of a year represented by the number of days between the specified start date and end date. You can use this function to identify the proportion of benefits or obligations during a specific period to those in a whole year.

## Engineering functions

BESSELI: returns the modified Bessel function In(x).

BESSELJ: returns the Bessel function Jn(x).

BESSELK: returns the modified Bessel function Kn(x).

BESSELY: returns the Bessel function Yn(x).

BIN2DEC: converts a binary number to decimal.

BIN2HEX: converts a binary number to hexadecimal.

BIN2OCT: converts a binary number to octal.

COMPLEX: converts real and imaginary coefficients to a complex number.

CONVERT: converts a number from one measurement system to another.

DEC2BIN: converts a decimal number to binary.

DEC2HEX: converts a decimal number to hexadecimal.

DEC2OCT: converts a decimal number to octal.

DELTA: tests whether two values are equal.

ERF: returns the error function.

ERF.PRECISE: returns the error function.

ERFC: returns the complementary error function.

ERFC.PRECISE: returns the complementary ERF function integrated between x and infinity.

GESTEP: tests whether a number is greater than a threshold value.

HEX2BIN: converts a hexadecimal number to binary.

HEX2DEC: converts a hexadecimal number to decimal.

HEX2OCT: converts a hexadecimal number to octal.

IMABS: returns the absolute value (modulus) of a complex number.

IMAGINARY: returns the imaginary coefficient of a complex number.

IMARGUMENT: returns the argument theta, which is an angle expressed in radians.

IMCONJUGATE: returns the complex conjugate of a complex number.

IMCOS: returns the cosine of a complex number.

IMDIV: returns the quotient of two complex numbers.

IMEXP: returns the exponential of a complex number.

IMLN: returns the natural logarithm of a complex number.

IMLOG10: returns the base-10 logarithm of a complex number.

IMLOG2: returns the base-2 logarithm of a complex number.

IMPOWER: returns a complex number raised to an integer power.

IMPRODUCT: returns the product of 1 to 255 complex numbers.

IMREAL: returns the real coefficient of a complex number.

IMSIN: returns the sine of a complex number.

IMSQRT: returns the square root of a complex number.

IMSUB: returns the difference between two complex numbers.

IMSUM: returns the sum of complex numbers.

OCT2BIN: converts an octal number to binary.

OCT2DEC: converts an octal number to decimal.

OCT2HEX: converts an octal number to hexadecimal.

## Financial functions

ACCRINT: returns the accrued interest for a security that pays periodic interest.

ACCRINTM: returns the accrued interest for a security that pays interest at maturity.

AMORDEGRC: uses a depreciation coefficient to return the depreciation for each accounting period.

AMORLINC: returns the depreciation for each accounting period.

COUPDAYBS: returns the number of days from the beginning of the current coupon period to the settlement date.

COUPDAYS: returns the number of days in the coupon period that contains the settlement date.

COUPDAYSNC: returns the number of days from the settlement date to the next coupon date.

COUPNCD: returns the next coupon date after the settlement date.

COUPNUM: returns the number of coupons payable between the settlement date and maturity date.

COUPPCD: returns the previous coupon date before the settlement date.

CUMIPMT: returns the cumulative interest paid between two periods.

CUMPRINC: returns the cumulative principal paid on a loan between two periods.

DB: uses the fixed-declining balance method to return the depreciation of an asset for a specified period.

DDB: uses the double-declining balance method or some other specified methods to return the depreciation of an asset for a specified period.

DISC: returns the discount rate for a security.

DOLLARDE: converts a dollar price, expressed as a fraction, to a dollar price, expressed as a decimal.

DOLLARFR: converts a dollar price, expressed as a decimal, to a dollar price, expressed as a fraction.

DURATION: returns the annual duration of a security with periodic interest payments.

EFFECT: returns the effective annual interest rate.

FV: returns the future value of an investment.

FVSCHEDULE: returns the future value of an initial principal after applying a series of compound interest rates.

INTRATE: returns the interest rate for a fully invested security.

IPMT: returns the interest payment for an investment for a given period.

IRR: returns the internal rate of return for a series of cash flows.

ISPMT: calculates the interest paid during a specific period of an investment.

MDURATION: returns the Macauley modified duration for a security with an assumed face value of USD 100.

MIRR: returns the internal rate of return where positive and negative cash flows are financed at different rates.

NOMINAL: returns the annual nominal interest rate.

NPER: returns the number of periods for an investment.

NPV: returns the net present value of an investment based on a series of periodic cash flows and a discount rate.

ODDFPRICE: returns the price per USD 100 face value of a security with an odd first period.

ODDFYIELD: returns the yield of a security with an odd first period.

ODDLPRICE: returns the price per USD 100 face value of a security with an odd last period.

ODDLYIELD: returns the yield of a security with an odd last period.

PMT: returns the periodic payment for an annuity.

PPMT: returns the payment on the principal for an investment for a given period.

PRICE: returns the price per USD 100 face value of a security that pays periodic interest.

PRICEDISC: returns the price per USD 100 face value of a discounted security.

PRICEMAT: returns the price per USD 100 face value of a security that pays interest at maturity.

PV: returns the present value of an investment.

RATE: returns the interest rate per period of an annuity.

RECEIVED: returns the amount received at maturity for a fully invested security.

SLN: returns the straight-line depreciation of an asset for one period.

SYD: returns the sum-of-years' digits depreciation of an asset for a specified period.

TBILLEQ: returns the bond-equivalent yield for a Treasury bill.

TBILLPRICE: returns the price per USD 100 face value for a Treasury bill.

TBILLYIELD: returns the yield for a Treasury bill.

VDB: uses a declining balance method to return the depreciation of an asset for a specified or partial period.

XIRR: returns the internal rate of return for a schedule of cash flows, which is not necessarily periodic.

XNPV: returns the net present value for a schedule of cash flows, which is not necessarily periodic.

YIELD: returns the yield on a security that pays periodic interest.

YIELDDISC: returns the annual yield for a discounted security, such as a Treasury bill.

YIELDMAT: returns the annual yield of a security that pays interest at maturity.

## Information functions

CELL: returns information about the format, location, or content of a cell.

ERROR.TYPE: returns a number corresponding to an error type.

INFO: returns information about the current operating environment.

ISBLANK: returns TRUE if the value is blank.

ISERR: returns TRUE if the value is any error value except #N/A.

ISERROR: returns TRUE if the value is any error value.

ISEVEN: returns TRUE if the number is even.

ISLOGICAL: returns TRUE if the value is a logical value.

ISNA: returns TRUE if the value is the error value #N/A.

ISNONTEXT: returns TRUE if the value is not text.

ISNUMBER: returns TRUE if the value is a number.

ISODD: returns TRUE if the number is odd.

ISREF: returns TRUE if the value is a reference.

ISTEXT: returns TRUE if the value is text.

N: returns a value converted to a number.

NA: returns the error value #N/A.

TYPE: returns a number indicating the data type of a value.

FORMULATEXT: returns a formula as a string.

## Logical functions

AND: returns TRUE if all of its arguments are TRUE.

FALSE: returns the logical value FALSE.

IF: specifies a logical test to perform.

IFERROR: returns a value that you specify if a formula evaluates to an error.

NOT: reverses the logic of its argument.

OR: returns TRUE if any argument is TRUE.

TRUE: returns the logical value TRUE.

## Lookup and reference functions

ADDRESS: returns a reference as text to a single cell in a worksheet.

AREAS: returns the number of areas in a reference.

CHOOSE: chooses a value from a list of values.

AGGREGATE: returns an aggregate in a list or database.

COLUMN: returns the column number of a reference.

COLUMNS: returns the number of columns in a reference.

HLOOKUP: searches for a value in the top row of an array and returns the value of a cell in the same column.

HYPERLINK: creates a shortcut that jumps to another location or opens a document stored on a network server, an intranet, or the Internet.

INDEX (Array): uses an index to choose a value from an array.

INDEX (Reference): uses an index to choose a value from a reference.

INDIRECT: returns a reference indicated by a text value.

LOOKUP (Array): searches for values in an array.

LOOKUP (Vector): searches for values in a vector.

MATCH: searches for values in a reference or array.

OFFSET: returns a reference offset from a given reference.

ROW: returns the row number of a reference.

ROWS: returns the number of rows in a reference.

TRANSPOSE: returns the transpose of an array.

VLOOKUP: searches for a value in the first column of an array and returns the value of a cell in the same row.

## Math and trigonometry functions

ABS: returns the absolute value of a number.

ACOS: returns the arccosine of a number.

ACOSH: returns the inverse hyperbolic cosine of a number.

AGGREGATE: returns an aggregate in a list or database.

ASIN: returns the arcsine of a number.

ASINH: returns the inverse hyperbolic sine of a number.

ATAN: returns the arctangent of a number.

ATAN2: returns the arctangent from x- and y-coordinates.

ATANH: returns the inverse hyperbolic tangent of a number.

CEILING: rounds a number to the nearest integer or to the nearest multiple of significance.

CEILING.PRECISE: returns a number that is rounded up to the nearest integer or to the nearest multiple of significance.

COMBIN: returns the number of combinations for a given number of objects.

COS: returns the cosine of a number.

COSH: returns the hyperbolic cosine of a number.

DEGREES: converts radians to degrees.

EVEN: rounds a number up to the nearest even integer.

EXP: returns e raised to the power of a given number.

FACT: returns the factorial of a number.

FACTDOUBLE: returns the double factorial of a number.

FLOOR: rounds a number down, towards zero, to the nearest multiple of significance.

FLOOR.PRECISE: returns a number that is rounded down to the nearest integer or to the nearest multiple of significance.

GCD: returns the greatest common divisor.

INT: rounds a number down to the nearest integer.

ISO.CEILING: returns a number that is rounded up to the nearest integer or to the nearest multiple of significance.

LCM: returns the least common multiple.

LN: returns the natural logarithm of a number.

LOG: returns the logarithm of a number to a specified base.

LOG10: returns the base-10 logarithm of a number.

MDETERM: returns the matrix determinant of an array.

MINVERSE: returns the matrix inverse of an array.

MMULT: returns the matrix product of two arrays.

MOD: returns the remainder from division.

MROUND: returns a number rounded to the desired multiple.

MULTINOMIAL: returns the multinomial of a set of numbers.

ODD: rounds a number up to the nearest odd integer.

PI: returns the value of pi.

POWER: returns the result of a number raised to a power.

PRODUCT: multiplies its arguments.

QUOTIENT: returns the integer portion of a division.

RADIANS: converts degrees to radians.

RAND: returns a random number between 0 and 1.

RANDBETWEEN: returns a random number between specified numbers.

ROMAN: converts an Arabic numeral to Roman in text format.

ROUND: rounds a number to a specified number of digits.

ROUNDDOWN: rounds a number down, towards zero.

ROUNDUP: rounds a number up, away from zero.

SERIESSUM: returns the sum of a power series based on the formula.

SIGN: returns the sign of a number.

SIN: returns the sine of the given angle.

SINH: returns the hyperbolic sine of a number.

SQRT: returns a positive square root.

SQRTPI: returns the square root of a number multiplied by pi.

SUBTOTAL: returns a subtotal in a list or database.

SUM: adds its arguments.

SUMIF: adds the cells specified by the given criteria.

SUMIFS: adds the cells that meet multiple criteria in a range.

SUMPRODUCT: returns the sum of the products of corresponding array components.

SUMSQ: returns the sum of the squares of arguments.

SUMX2MY2: returns the sum of the difference of squares of corresponding values in two arrays.

SUMX2PY2: returns the sum of the sum of squares of corresponding values in two arrays.

SUMXMY2: returns the sum of squares of differences of corresponding values in two arrays.

TAN: returns the tangent of a number.

TANH: returns the hyperbolic tangent of a number.

TRUNC: truncates a number to an integer.

## Statistical functions

AVEDEV: returns the average of the absolute deviations of data points from their mean.

AVERAGE: returns the average of its arguments.

AVERAGEA: returns the average of its arguments, including numbers, text, and logical values.

AVERAGEIF: returns the average (arithmetic mean) of all cells that meet the given criteria in a range.

AVERAGEIFS: returns the average (arithmetic mean) of all cells that meet multiple criteria.

BETA.DIST: returns the beta cumulative distribution function.

BETA.INV: returns the inverse of the cumulative distribution function for a specified beta distribution.

BETADIST: returns the beta cumulative distribution function.

BETAINV: returns the inverse of the cumulative distribution function for a specified beta distribution.

BINOM.DIST: returns the individual term binomial distribution probability.

BINOM.INV: returns the smallest value for which the cumulative binomial distribution is less than or equal to a criterion value.

BINOMDIST: returns the individual term binomial distribution probability.

CHIDIST: returns the one-tailed probability of the chi-squared distribution.

CHIINV: returns the inverse of the one-tailed probability of the chi-squared distribution.

CHISQ.DIST: returns the chi-squared distribution.

CHISQ.DIST.RT: returns the right-tailed probability of the chi-squared distribution.

CHISQ.INV: returns the inverse of the left-tailed probability of the chi-squared distribution.

CHISQ.INV.RT: returns the inverse of the one-tailed probability of the chi-squared distribution.

CHISQ.TEST: returns the test for independence.

CHITEST: returns the test for independence.

CONFIDENCE: returns the confidence interval for a population mean.

CONFIDENCE.NORM: uses a normal distribution to return the confidence interval for a population mean.

CONFIDENCE.T: uses a Student's t distribution to return the confidence interval for a population mean.

CORREL: returns the correlation coefficient between two datasets.

COUNT: counts how many numbers are in the list of arguments.

COUNTA: counts how many values are in the list of arguments.

COUNTBLANK: counts the number of blank cells within a range.

COUNTIF: counts the number of cells that meet the given criteria within a range.

COUNTIFS: counts the number of cells that meet multiple criteria within a range.

COVAR: returns covariance, which is the average of the products of paired deviations.

COVARIANCE.P: returns covariance, which is the average of the products of deviations for each data point pair in two datasets.

COVARIANCE.S: returns the sample covariance, which is the average of the products of deviations for each data point pair in two datasets.

CRITBINOM: returns the smallest value for which the cumulative binomial distribution is greater than or equal to a criterion value.

DEVSQ: returns the sum of squares of deviations.

EXPON.DIST: returns the exponential distribution.

EXPONDIST: returns the exponential distribution.

F.DIST: returns the F probability distribution.

F.DIST.RT: returns the F probability distribution.

F.INV: returns the inverse of the F probability distribution.

F.INV.RT: returns the inverse of the F probability distribution.

F.TEST: returns the result of an F-test.

FDIST: returns the F probability distribution.

FINV: returns the inverse of the F probability distribution.

FISHER: returns the Fisher transformation.

FISHERINV: returns the inverse of the Fisher transformation.

FORECAST: returns a value along a linear trend.

FREQUENCY: returns a frequency distribution as a vertical array.

FTEST: returns the result of an F-test.

GAMMA.DIST: returns the gamma distribution.

GAMMA.INV: returns the inverse of the gamma cumulative distribution.

GAMMADIST: returns the gamma distribution.

GAMMAINV: returns the inverse of the gamma cumulative distribution.

GAMMALN: returns the natural logarithm of the gamma function, Γ(x).

GAMMALN.PRECISE: returns the natural logarithm of the gamma function, Γ(x).

GEOMEAN: returns the geometric mean.

GROWTH: returns the y-values for a series of new x-values along an exponential trend.

HARMEAN: returns the harmonic mean.

HYPGEOM.DIST: returns the hypergeometric distribution.

HYPGEOMDIST: returns the hypergeometric distribution.

INTERCEPT: returns the intercept of the linear regression line.

KURT: returns the kurtosis of a dataset.

LARGE: returns the k-th largest value in a dataset.

LINEST: returns the parameters of a linear trend.

LOGEST: returns the parameters of an exponential trend.

LOGINV: returns the inverse of the lognormal cumulative distribution.

LOGNORM.DIST: returns the lognormal distribution of x.

LOGNORM.INV: returns the inverse of the lognormal cumulative distribution function of x.

LOGNORMDIST: returns the cumulative lognormal distribution.

MAX: returns the maximum value in a list of arguments.

MAXA: returns the maximum value in a list of arguments, including numbers, text, and logical values.

MEDIAN: returns the median of the given numbers.

MIN: returns the minimum value in a list of arguments.

MINA: returns the smallest value in a list of arguments, including numbers, text, and logical values.

MODE: returns the most common value in a dataset.

MODE.MULT: returns a vertical array of the most frequently occurring or repetitive values in an array or range of data.

MODE.SNGL: returns the most frequently occurring or repetitive value in an array or range of data.

NEGBINOM.DIST: returns the negative binomial distribution.

NEGBINOMDIST: returns the negative binomial distribution.

NORM.DIST: returns the normal distribution for the specified mean and standard deviation.

NORM.INV: returns the inverse of the normal cumulative distribution for the specified mean and standard deviation.

NORM.S.DIST: returns the standard normal cumulative distribution.

NORM.S.INV: returns the inverse of the standard normal cumulative distribution.

NORMDIST: returns the normal cumulative distribution.

NORMINV: returns the inverse of the normal cumulative distribution.

NORMSDIST: returns the standard normal cumulative distribution.

NORMSINV: returns the inverse of the standard normal cumulative distribution.

PEARSON: returns the Pearson product moment correlation coefficient.

PERCENTILE: returns the k-th percentile of values for a set of data.

PERCENTILE.EXC: returns the k-th percentile of values for a set of data, where k is in the range of 0 to 1, exclusive.

PERCENTILE.INC: returns the k-th percentile of values in a range.

PERCENTRANK: returns the rank of a value in a dataset as a percentage of the dataset.

PERCENTRANK.EXC: returns the rank of a value in a dataset as a percentage (in the range of 0 to 1, exclusive) of the dataset.

PERCENTRANK.INC: returns the rank of a value in a dataset as a percentage (in the range of 0 to 1, inclusive) of the dataset.

PERMUT: returns the number of permutations for a given number of objects.

POISSON: returns the Poisson distribution.

POISSON.DIST: returns the Poisson distribution.

PROB: returns the probability that values in a range are between two limits.

QUARTILE: returns the quartile of a dataset.

QUARTILE.EXC: returns the quartile of a dataset, based on percentile values in the range of 0 to 1, exclusive.

QUARTILE.INC: returns the quartile of a dataset, based on percentile values in the range of 0 to 1, inclusive.

RANK: returns the rank of a number in a list of numbers. The rank of a number is its size relative to other values in a list.

RANK.AVG: returns the rank of a number in a list of numbers. The rank of a number is its size relative to other values in a list.

RANK.EQ: returns the rank of a number in a list of numbers. The rank of a number is its size relative to other values in a list.

RSQ: returns the square of the Pearson product moment correlation coefficient.

SKEW: returns the skewness of a distribution.

SLOPE: returns the slope of the linear regression line.

SMALL: returns the k-th smallest value in a dataset.

STANDARDIZE: returns a normalized value.

STDEV: estimates the standard deviation based on a sample.

STDEV.P: calculates the standard deviation based on the entire population.

STDEV.S: estimates the standard deviation based on a sample.

STDEVA: estimates the standard deviation based on a sample, including numbers, text, and logical values.

STDEVP: calculates the standard deviation based on the entire population.

STDEVPA: calculates the standard deviation based on the entire population, including numbers, text, and logical values.

STEYX: returns the standard error of the predicted y-value for each x in the regression.

T.DIST: returns the Student's t-distribution.

T.DIST. 2T: returns the two-tailed Student's t-distribution.

T.DIST.RT: returns the right-tailed Student's t-distribution.

T.INV: returns the left-tailed inverse of the Student's t-distribution.

T.INV. 2T: returns the two-tailed inverse of the Student's t-distribution.

T.TEST: returns the probability associated with a Student's t-test.

TDIST: returns the Student's t-distribution.

TINV: returns the inverse of the Student's t-distribution.

TREND: returns the y-values of a specified array along a linear trend.

TRIMMEAN: returns the mean of the interior of a dataset.

TTEST: returns the probability associated with a Student's t-test.

VAR: estimates variance based on a sample.

VAR.P: calculates variance based on the entire population.

VAR.S: estimates variance based on a sample.

VARA: estimates variance based on a sample, including numbers, text, and logical values.

VARP: calculates variance based on the entire population.

VARPA: calculates variance based on the entire population, including numbers, text, and logical values.

WEIBULL: returns the Weibull distribution.

WEIBULL.DIST: returns the Weibull distribution.

Z.TEST: returns the one-tailed probability-value of a z-test.

ZTEST: returns the one-tailed probability-value of a z-test.

## Text functions

CHAR: returns the character specified by a code number.

CLEAN: removes all non-printable characters from text.

CODE: returns a numeric code for the first character in a text string.

CONCATENATE: joins several text items into one text item.

DOLLAR: uses the $ (dollar) currency format to convert a number to text.

EXACT: checks whether two text values are identical.

FIND: finds one text value within another (case-sensitive).

FIXED: formats a number as text with a fixed number of decimal places.

LEFT: returns the leftmost characters from a text value.

LEN: returns the number of characters in a text string.

LOWER: converts text to lowercase.

MID: returns a specific number of characters from a text string starting at the position that you specify.

PROPER: capitalizes the first letter in each word of a text value.

REPLACE: replaces characters within text.

REPT: repeats text a given number of times.

RIGHT: returns the rightmost characters from a text value.

SEARCH: finds one text value within another (case-insensitive).

SUBSTITUTE: substitutes new text for old text in a text string.

T: converts its arguments to text.

TEXT: formats a number and converts it to text.

TRIM: removes spaces from text.

UPPER: converts text to uppercase.

VALUE: converts a text argument to a number.