Speed Math Quiz

Name:

Date:

Instructions: How fast can you solve these mental math problems?

1.
What is 25 × 4?
A
100
B
95
C
90
D
110
2.
What is 150 ÷ 6?
A
30
B
20
C
35
D
25
3.
What is 18 + 27 + 15?
A
55
B
62
C
60
D
58
4.
What is 9 × 11?
A
89
B
101
C
99
D
109
5.
What is 200 − 87?
A
113
B
133
C
123
D
103
6.
What is 15% of 200?
A
20
B
25
C
30
D
35
7.
What is 12 × 15?
A
180
B
170
C
190
D
160
8.
What is the square root of 144?
A
11
B
14
C
13
D
12
9.
What is 3/4 expressed as a percentage?
A
80%
B
60%
C
75%
D
70%
10.
What is 456 + 389?
A
835
B
855
C
825
D
845
11.
What is 17 × 13?
A
221
B
211
C
201
D
231
12.
What is 1,000 ÷ 8?
A
115
B
125
C
120
D
130
13.
What is 2³ × 3² (2 cubed times 3 squared)?
A
48
B
72
C
64
D
54
14.
If a shirt costs $45 and is discounted by 20%, what is the sale price?
A
$36
B
$34
C
$40
D
$38
15.
What is 999 × 5?
A
4,985
B
4,990
C
5,005
D
4,995

Answer Key

Question 1

A. 100

25 × 4 = 100. A quick trick: 25 × 4 is the same as 100, since four quarters make a dollar.

Question 2

D. 25

150 ÷ 6 = 25. You can break this down: 120 ÷ 6 = 20, and 30 ÷ 6 = 5, so 20 + 5 = 25.

Question 3

C. 60

18 + 27 + 15 = 60. A helpful trick: 18 + 27 = 45, then 45 + 15 = 60.

Question 4

C. 99

9 × 11 = 99. One trick: 9 × 11 = (10 × 11) − 11 = 110 − 11 = 99.

Question 5

A. 113

200 − 87 = 113. Subtract 87 from 200: 200 − 80 = 120, then 120 − 7 = 113.

Question 6

C. 30

15% of 200 = 30. Calculate 10% (20) plus 5% (10) to get 30.

Question 7

A. 180

12 × 15 = 180. Break it down: 12 × 10 = 120, and 12 × 5 = 60, so 120 + 60 = 180.

Question 8

D. 12

The square root of 144 is 12, because 12 × 12 = 144.

Question 9

C. 75%

3/4 = 0.75 = 75%. Divide 3 by 4 to get 0.75, then multiply by 100.

Question 10

D. 845

456 + 389 = 845. Add 456 + 400 = 856, then subtract 11 to get 845.

Question 11

A. 221

17 × 13 = 221. Break it down: 17 × 10 = 170, and 17 × 3 = 51, so 170 + 51 = 221.

Question 12

B. 125

1,000 ÷ 8 = 125. Think of it as 1000/8 = 500/4 = 250/2 = 125.

Question 13

B. 72

2³ = 8 and 3² = 9. So 8 × 9 = 72.

Question 14

A. $36

20% of $45 = $9. So the sale price is $45 − $9 = $36.

Question 15

D. 4,995

999 × 5 = 4,995. A quick trick: 1,000 × 5 = 5,000, then subtract 5 to get 4,995.

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