Lesson 5 Quiz: Numbers and Arithmetic

1. What is the difference between an integer and a float?

A. An integer has a decimal point; a float is a whole number. B. An integer is a whole number; a float has a decimal point. C. An integer is text; a float is a number. D. An integer can only be negative; a float can only be positive.

2. What does `7 / 2` give, and why is it a float?

A. `3.5` — division in Python always produces a float. B. `3` — division in Python always produces an integer. C. `3.5` — division produces a float only when the answer has a remainder. D. `4` — division rounds up to the nearest whole number.

3. What do `//` and `%` compute? Give the results for `9 // 2` and `9 % 2`.

A. `//` is the remainder, `9 // 2 = 1`; `%` is floor division, `9 % 2 = 4`. B. `//` is floor (whole-number) division, `9 // 2 = 1`; `%` is the remainder, `9 % 2 = 4`. C. `//` is floor (whole-number) division, `9 // 2 = 4`; `%` is the remainder, `9 % 2 = 1`. D. `//` and `%` both give the remainder: `9 // 2 = 1` and `9 % 2 = 1`.

4. Why does `2 + 3 * 4` give `14` and not `20`?

A. Addition happens before multiplication, so it is `5 * 4`. B. Python reads the numbers from right to left, so it is `4 * 3 + 2`. C. Python adds first, then multiplies: `(2 + 3) * 4 = 20`, but the answer is printed wrong. D. Multiplication happens before addition, so it is `2 + 12`.

5. Why does `"5" + "3"` give `53` while `5 + 3` gives `8`?

A. The quoted values are numbers, so `+` adds them; the unquoted values are text, so `+` joins them. B. Python reads `"5" + "3"` as `5 + 3 = 8`, but prints it as `53` by mistake. C. The quoted values are text, so `+` joins them; the unquoted values are numbers, so `+` adds them. D. The quotes make the numbers bigger, so `5 + 3` becomes `53`.