IMO Practice Test — Basic Subtraction
6 Questions • 15 min • Olympiad level
15:00
Question 1 of 6
What number should be subtracted from 12 to get 7?
4
5
6
7
Explanation: 12 - ? = 7, so ? = 5
Question 2 of 6
15 – 3 – 2 = ?
8
9
10
11
Explanation: 15-3=12, 12-2=10
Question 3 of 6
Find the missing number: 18 – ___ = 9
7
8
9
10
Explanation: 18 - 9 = 9
Question 4 of 6
47 – 23 = ? (Without regrouping)
22
23
24
25
Explanation: Ones:7-3=4, Tens:4-2=2 → 24
Question 5 of 6
Which number sentence is correct?
12-4=9
15-7=8
16-9=6
13-5=9
Explanation: 15-7=8 is correct; others are wrong
Question 6 of 6
There are 20 children on a bus. 7 children get off. How many are left?
12
13
14
15
Explanation: 20 - 7 = 13