Numbers and math

Numbers are different from text: they’re written without quotes. When you leave the quotes off, Python actually does the math:

Inputs (for input())

One value per line — read in order by input().

▶ Run

Output

See that? 5 + 3 was calculated and came out as 8, while "5 + 3" was printed as plain text. Quotes = text, no quotes = number.

Math operations

Sign	Operation	Example	Result
+	addition	7 + 2	9
-	subtraction	7 - 2	5
*	multiplication	7 * 2	14
/	division	7 / 2	3.5
//	whole division	7 // 2	3
%	remainder	7 % 2	1
**	power	7 ** 2	49

Here’s how to remember the // and % pair: share 7 candies among 2 kids — each one gets 7 // 2 = 3 candies, and 7 % 2 = 1 candy is left over. 🍬

Python — a super-calculator

How many seconds are there in a day? Easy:

Inputs (for input())

One value per line — read in order by input().

▶ Run

Output

Look at the second line: 2 to the power of 100 — an ordinary calculator can’t handle it, but Python doesn’t even blink. 😎

Missions

Mission

How many hours in a year?

+10 XP

Have Python calculate how many hours are in a year. (Don’t type the answer yourself — use multiplication!)

Inputs (for input())

One value per line — read in order by input().

▶ Run

Output

Mission

Sharing apples

+15 XP

17 apples, 5 kids. Use // and % to work out: how many apples does each kid get, and how many are left over?

Inputs (for input())

One value per line — read in order by input().

▶ Run

Output

Mission

The power of powers

+10 XP

There’s a famous number in the world of computers: 2 to the power of 10. Have Python calculate it and see the result.

Inputs (for input())

One value per line — read in order by input().

▶ Run

Output

Module progress 0 / 12

Total XP: 0

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Next lesson: variables — boxes for storing information. One of the most important ideas in all of programming. Continue →