Formulas can work with integer numbers as well as with real numbers.

Real numbers

You can type many real numbers by using a decimal notation, for instance 3.14159, 299792.5, or -0.000123456789. For very large or small numbers, you can use the e-notation: 6.022·10²³ is typed as 6.022e23 or 6.022e+23, and -1.6021917·10^-19 is typed as -1.6021917e-19. You can use also use the percent notation: 0.157 can be typed as 15.7%.

There are some limitations as to the values that real numbers can have in Praat. The numbers must lie between -10³⁰⁸ and +10³⁰⁸. If you type

the outcome will be

but if you type

the outcome will be

Another limitation is that the smallest non-zero numbers lie near -10^-308 and +10^-308. If you type

the outcome will be

but if you type

the outcome will be

Finally, the precision of real numbers is limited by the number of bits that every real number is stored with in the computer, namely 64. For instance, if you type

the outcome will be

because only 16 digits of precision are stored. This can lead to unexpected results caused by rounding. For instance, the formula

will result in

rather than the correct value of 1e-17. This is because the numbers 0.34999999999999999 and 0.35 cannot be distinguished in the computer's memory. If you simply type

the outcome will be

(as in this example, the calculator will always come up with the minimum number of digits needed to represent the number unambiguously).

Another example of inaccuracy is the formula

Because of rounding errors, the result will be

Integer numbers

Formulas can work with integer (whole) numbers between -1,000,000,000,000,000 and +1,000,000,000,000,000. You type them without commas and without the plus sign: 337, -848947328345289.

You can work with larger numbers than that (up to 10³⁰⁸), but there will again be rounding errors. For instance, the formula

correctly yields

but the formula

yields an incorrect outcome:

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• Formulas 2. Representations