Data Types and Operations

Concept: Arithmetic

In these exercises, you will use integers for whole numbers such as 7, and floats for numbers such as 3.75. Arithmetic operators combine these values.

Arithmetic operators

+ add, - subtract, * multiply
/ divide — for integers and floats, gives a float (10 / 2 is 5.0)
// floor division — divide and round the result down toward negative infinity. For example, 7 // 2 is 3, while -7 // 2 is -4.
% modulo — the remainder left over (7 % 2 is 1)
** power (2 ** 3 is 8)

print("10 + 3 =", 10 + 3)
print("10 / 3 =", 10 / 3)
print("10 // 3 =", 10 // 3)
print("10 % 3 =", 10 % 3)
print("2 ** 3 =", 2 ** 3)

Each line shows the operator and the answer it produces.

Dividing integers and floats

With the integer and float values used here, / returns a float even when the division is exact. For example, 6 / 3 produces 2.0.

Rounding

round(value, n) returns a number rounded to n decimal places. It does not control how many trailing zeroes are displayed. For example, round(2.0, 2) still displays as 2.0 when printed normally.

average = 37 / 3
print(average)
print(round(average, 2))

Order of operations

Python follows normal maths order — * and / happen before + and -. Use parentheses when you want a different order:

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

Your turn

Add two lines: print a floor-divided by b, then print the remainder of a divided by b.

a = 17
b = 5
# add two prints: floor division first, then the remainder

Expected output

3
2

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