The Mental Math Quiz

By: Talin Vartanian
Estimated Completion Time
1 min
The Mental Math Quiz
Image: JGI/Tom Grill / Blend Images / Getty Images

About This Quiz

This quiz will take a look at 35 math-related questions that involve various mathematical concepts. Some of these include word problems, addition, subtraction, exponents, square roots and cubed numbers.

Percentages are also involved in this quiz. For example, do you know what 20% of 20 is? An easier way to look at this is 10% of 20, which is 2. When you take 10% of a number, you're just removing that 0 from the end. So when you take away 0 from the end of 20, you get 2, which is 10% of 20. Now to find out what 20% of 20 is, just double that 2 number to get 4. Thus, 20% of 20 is 4.

We'll also take a look at some exponents in this quiz. For instance, do you know what 3³ is? One way to look at this problem is like this: 3(3)(3), which is 27. To cube a number means to multiply that number three times. This is also similar to squaring a number, which is done with the symbol: ². To square a number means to take a number and multiply it by itself. For example, 2² is 4, since 2(2) is 4.

Now that the warm-up is done, it's time to sharpen your math skills with this mental math quiz!

Do you know what the square root of 144 is?
12
11
14
18
Correct Answer
Wrong Answer

The square root of 144 is 12. In other words, 12 times 12 is 144.

Advertisement

What is 6 multiplied by 8?
68
46
48
42
Correct Answer
Wrong Answer

When you multiply 6 by 8, you get 48. This is an even number.

Advertisement

What is 50 divided by 2?
25
20
15
10
Correct Answer
Wrong Answer

The answer is 25. In other words, if you multiply 2 by 25, you get 50.

Advertisement

Can you guess what the cube root of 27 is?
1
2
3
7
Correct Answer
Wrong Answer

The answer is 3. The cube root of 27 means that 3(3)(3) = 27.

Advertisement

Do you think you know what 10² is?
20
100
110
50
Correct Answer
Wrong Answer

10² is 100. In other words, 10 times 10 is 100.

Advertisement

Do you know what 2³ is?
10
6
8
4
Correct Answer
Wrong Answer

8 is the correct answer. To cube a number means to multiply it three times. Since 2(2)(2) = 8, the number 2 cubed is 8.

Advertisement

What is 27 + 19?
34
49
47
46
Correct Answer
Wrong Answer

46 is the right answer. An easier way to look at this is 27 + 20 is 47, minus 1 is 46.

Advertisement

Try and guess what 52 - 23 is!
29
28
26
21
Correct Answer
Wrong Answer

29 is the right answer. Sometimes it's easier to round one of the numbers in the question to make the computation easier. For instance, instead of trying to calculate 52 - 23, try 50 - 23, which is easier to compute to 27, then add 2, which is 29.

Advertisement

What is 0 divided by 1?
1
0
-1
Cannot be computed
Correct Answer
Wrong Answer

The right answer is 0. 0 divided by any number is still 0.

Advertisement

What is 2 divided by 0?
1
2
Cannot be computed
0
Correct Answer
Wrong Answer

The answer cannot be computed. You can't take a number and divide it by 0.

Advertisement

Can you guess what -1 + 1 equals?
2
-2
1
0
Correct Answer
Wrong Answer

The correct answer is 0. Another way to look at the question is 1 - 1, which is 0.

Advertisement

What is -20 divided by -2?
-12
10
15
-10
Correct Answer
Wrong Answer

10 is the right answer. When you divide two negative numbers, the answer is a positive number. So, -20 divided by -2 equals 10.

Advertisement

What is -4 multiplied by 9?
-38
38
36
-36
Correct Answer
Wrong Answer

-36 is the correct answer. When you multiply a positive and a negative number together, the answer is a negative number. So, -4 multiplied by 9 is -36.

Advertisement

Do you think you know what -2 - (-9) is?
11
-7
7
-11
Correct Answer
Wrong Answer

7 is the correct answer. When you are subtracting these two negative numbers, another way to look at it is -2 + 9, which means the same thing as -2 - (-9). So, -2 + 9 is 7, since you're subtracting 2 from 9.

Advertisement

Try and guess what (-10 +2)/2 is!
6
4
-4
-6
Correct Answer
Wrong Answer

-4 is the right answer. Let's walk through this problem: -10 + 2 is -8, because you're taking away 2 from -10. Now you take -8 and divide it by 2, which is -4.

Advertisement

What is (2 + 1)/(0 + 1)?
3
2
1
0
Correct Answer
Wrong Answer

3 is the right answer. Let's walk through this problem, starting with the numerator: 2 + 1 is 3. The denominator, 0 + 1 is 1. Now you take 3 and divide it by 1, which is 3.

Advertisement

What is (2 -1)³?
2
1
3
9
Correct Answer
Wrong Answer

1 is the right answer. Do the problem in parentheses first, so 2-1 is 1. Now the problem is 1³, which is just 1.

Advertisement

What is the square root of 0?
Infinity
-1
0
1
Correct Answer
Wrong Answer

The square root of 0 is still 0. In other words, 0 times 0 is still 0.

Advertisement

Do you know what the square root of -1 is?
-2
1
0
i
Correct Answer
Wrong Answer

i is the correct answer. i means "imaginary number" in math terms. Don't worry if you didn't get this one right - it's complicated!

Advertisement

Try and guess what (-2)² is!
4
-4
2
-2
Correct Answer
Wrong Answer

(-2)² is 4. Another way to look at this problem is like this: -2 times -2 is 4, since two negative numbers become a positive number.

Advertisement

Think you can figure out what 20% of 50 is?
5
10
20
15
Correct Answer
Wrong Answer

The answer is 10. Let's work this problem out: 10% of 50 would be 5 (just take that 0 away from the end). Now just double the 5 to get 10, which is 20% of 50.

Advertisement

What is 5% of 10?
10
5
1
.5
Correct Answer
Wrong Answer

.5 is the answer. If we know that 10% of 10 is 1 (you just take that 0 away from the end of 10, leaving 1), then we can just halve that 1 to .5, since we want to know what 5% of 10 is.

Advertisement

Can you figure out what 4² + 3² is?
19
23
22
25
Correct Answer
Wrong Answer

25 is the correct answer. 4² is 16, since 4 times 4 is 16. And 3² is 9, since 3 times 3 is 9. So, 16 + 9 is 25.

Advertisement

What is 3³ + 1³?
27
28
29
24
Correct Answer
Wrong Answer

The right answer is 28. 3³ is 27, since 3(3)(3) is 27. 1³ is still 1, since 1(1)(1) is 1. So, 27 + 1 is 28!

Advertisement

Can you guess what 1,256,498 divided by 1 is?
1,256,498
1
0
Cannot be computed
Correct Answer
Wrong Answer

The answer is 1,256,498, since ANY number divided by 1 is still the same number. 2 divided by 1 is still 2, 500 divided by 1 is still 500, and so on.

Advertisement

Sally has two apples, three oranges and one kiwi. If I take two oranges away from her, how many pieces of fruit does she have now?
4
2
6
8
Correct Answer
Wrong Answer

4 is the right answer. Sally has a total of six fruits in the beginning. If I take two oranges from her, now she has four pieces of fruit.

Advertisement

An item at a store costs $2.10. If I give the cashier a $5 bill, how much change can I expect back?
$2.90
$1.80
$2.70
$2.80
Correct Answer
Wrong Answer

$2.90 is the right answer. In other words, 5 - 2.1 is 2.9.

Advertisement

An item at a store costs $20, but I have a coupon for 10% off. How much does the item cost now?
$16
$14
$18
$17
Correct Answer
Wrong Answer

The item now costs $18. Here's why: 10% of $20 is $2 (you just remove that 0 from the end of 20 to get 2). Now, you just subtract $2 from $20, which leaves $18.

Advertisement

It's 9:00 now. What time will it be 3 hours and 14 minutes from now?
12:14
11:14
1:14
2:14
Correct Answer
Wrong Answer

The answer is 12:14. If it's 9:00 now, in 3 hours it will be 12:00, since 9 + 3 = 12. Since we know it's 12:00, we just add 14 to get 12:14. Doesn't matter if we're near noon or midnight.

Advertisement

It's 3:30 now. What time was it one hour and 28 minutes ago?
2:13
2:17
2:28
2:02
Correct Answer
Wrong Answer

2:02 is the right answer. If it's 3:30 now, one hour ago it was 2:30. Now we just take 28 minutes from 30 minutes, which leaves 2 minutes. Thus, the answer is 2:02.

Advertisement

Try and solve this problem: (2+2)² - (1-1)³
13
16
12
14
Correct Answer
Wrong Answer

16 is the right answer. (2+2) is 4, and 4² is 16. (1-1) is 0, and 0³ is still 0. So, 16 - 0 is 16.

Advertisement

What is (√100)²?
-100
10
100
-10
Correct Answer
Wrong Answer

100 is the correct answer. The "√" and the "²" cancel each other out in this problem. Here's another way to look at this: the square root of 100 is 10. 10², or 10 times 10, is 100.

Advertisement

What is √25 + √16?
8
9
5
4
Correct Answer
Wrong Answer

9 is the right answer. The square root of 25 is 5. The square root of 16 is 4. 5 + 4 is 9.

Advertisement

What is 7 times 7?
77
48
47
49
Correct Answer
Wrong Answer

7 times 7 is 49. Another way to look at this is 7², which is 49.

Advertisement

What is the answer to this problem: (2³)/(2²)?
16
8
4
2
Correct Answer
Wrong Answer

2 is the right answer. 2³ is 8, since 2(2)(2) is 8. 2 squared is 4, since 2(2) is 4. 8 divided by 4 is 2.

Advertisement

You Got:
/35
JGI/Tom Grill / Blend Images / Getty Images