PythonLesson 3 of 16

Numbers and operators in Python

Python is a handy calculator that also keeps results in variables. Let's add up a café bill and share a pizza fairly.

Key points

+, -, * and / work like on a calculator
/ always returns a decimal: 780 / 4 = 195.0
// divides and drops the remainder, % gives the remainder
** raises to a power: 2 ** 3 = 8
round(x, 2) keeps two digits after the point

Example

coffee = 180croissant = 120total = 3 * coffee + 2 * croissantprint("Total:", total)print("Each of 4 pays:", total / 4)print("Squared:", 12 ** 2)print(round(10 / 3, 2))

Multiplication runs before addition, just like in school. Dividing with / gives 195.0, with a decimal point even when it divides evenly.

Task

How to use the editor⌘ Enter or Ctrl Enter runs the code, ⇧ ⌘ Enter checks the task.Tab and Shift Tab indent the line or the selection; Esc, then Tab leaves the editor.The check compares what the program printed with the task; spaces at line ends do not matter.After two failed checks you may open the solution. Your code is kept in this browser.

17 pizza slices, 5 friends. Work out how many whole slices each friend gets (each) and how many are left (left).

slices = 17friends = 5# TODO: whole slices per friend and slices left overeach = 0left = 0print("Each gets:", each)print("Left over:", left)

slices = 17
friends = 5
# TODO: whole slices per friend and slices left over
each = 0
left = 0
print("Each gets:", each)
print("Left over:", left)

Output

What your program prints appears here.