Lesson 1 reading

In the lesson we only used +. Python has a full set of math operators:

Operator	What it does	Example	Result
+	addition	7 + 2	9
-	subtraction	7 - 2	5
*	multiplication	7 * 2	14
/	division	7 / 2	3.5
//	floor division	7 // 2	3
%	remainder (modulo)	7 % 2	1
**	power	7 ** 2	49

Division and types

Remember integers and floats from the lesson? Division connects to types in a sneaky way: / always returns a float, even when the numbers divide evenly:

print(10 / 2)   # 5.0  — a float, not 5
print(10 // 3)  # 3    — floor division throws away the decimal part

Remainder

// and % are a team. // tells you how many times something fits, and % tells you what is left over:

print(17 // 5)  # 3  — 5 fits into 17 three times
print(17 % 5)   # 2  — with 2 left over

This is how you answer questions like "if 17 students split into teams of 5, how many full teams are there, and how many students are left without a team?"

Try it

Before running each line, predict the answer. Then run it and check yourself:

print(2 ** 10)
print(100 / 8)
print(100 // 8)
print(100 % 8)