Divide, leave over, order up

Computing · Programming · ages 14-15

Name ______________________ Date ____________

What does this expression evaluate to: 2 * (3 + 4)
Answer: ______________
// keeps only the remainder of a division.
Circle one: True False
That same stopwatch shows 125 seconds. After you take out the full minutes, how many seconds are left over? (Hint: find 125 % 60.)
Answer: ______________
True or false: in the expression 2 * 3 + 4, the multiplication runs before the addition.
Circle one: True False
A timer holds 200 seconds. How many leftover seconds does 200 % 60 give?
Answer: ______________
What is the value of 2 * (3 + 4)?
- 10
- 11
- 14
A song lasts 197 seconds. How many seconds are left over after counting out full minutes? (Hint: find 197 % 60.)
Answer: ______________
You have 53 stickers to hand out in packs of 6. Using integer division, how many full packs of 6 can you make? (Hint: find 53 // 6.)
Answer: ______________
A cutscene lasts 137 seconds. How many whole minutes does 137 // 60 give?
Answer: ______________
What is the value of (5 + 3) * 2 - 4?
- 8
- 12
- 16

Answer key

For grown-ups. Fold this page away before handing over the rest.

14 · Parentheses run before multiplication, so the addition inside happens first.
False · // keeps the whole part. % is the one that keeps the remainder.
5 · The remainder operator gives you exactly what's left after dividing out the full minutes.
True · Multiplication outranks addition, so 2 * 3 is computed before 4 is added.
20 · Three 60s make 180, and 200 minus 180 leaves 20.
14 · Brackets run first, so 3 + 4 happens before the multiply.
17 · The remainder is whatever is left once you've pulled out all the complete 60-second minutes.
8 · Integer division tells you the whole number of packs, ignoring any leftover stickers.
2 · Two 60s make 120, and a third would need 180.
12 · Brackets first, then multiply, then subtract.