Arithmetic operators

Python can calculate with numbers. The common arithmetic operators are + for addition, - for subtraction, * for multiplication, and / for division. Division with / produces a float, even when the result is a whole number.

print(8 + 2)
print(8 - 2)
print(8 * 2)
print(8 / 2)

10
6
16
4.0

Whole-number division and remainder

For nonnegative numbers and a positive divisor, // finds how many whole groups fit, and % finds the remainder. This is useful when converting a total number of minutes into hours and remaining minutes.

total_minutes = 135
hours = total_minutes // 60
remaining_minutes = total_minutes % 60
print(hours)
print(remaining_minutes)

2
15

Powers and grouping

The ** operator raises a number to a power. Powers are evaluated before multiplication and division, which are evaluated before addition and subtraction. Parentheses make the intended order explicit.

print(2 ** 3)
print(2 + 3 * 4)
print((2 + 3) * 4)

8
14
20

Why this works

Use / when you want a division result that may contain a fraction. For nonnegative totals and a positive unit size, // gives complete units and % gives what remains. For example, 135 minutes is 135 // 60 complete hours and 135 % 60 remaining minutes.

Practice

Set sessions to 3 and minutes_per_session to 25. Calculate total_minutes with multiplication, then print the whole hours and remaining minutes using // and %.

Try another case

Convert 130 minutes into whole hours and remaining minutes.