# The Mental Math Quiz

EDUCATION

By: Talin Vartanian

5 Min Quiz

# Do you know what the square root of 144 is?

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

# What is 6 multiplied by 8?

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

# What is 50 divided by 2?

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

# Can you guess what the cube root of 27 is?

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

# Do you think you know what 10² is?

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

# Do you know what 2³ is?

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.

# What is 27 + 19?

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

# Try and guess what 52 - 23 is!

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.

# What is 0 divided by 1?

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

# What is 2 divided by 0?

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

# Can you guess what -1 + 1 equals?

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

# What is -20 divided by -2?

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

# What is -4 multiplied by 9?

-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.

# Do you think you know what -2 - (-9) is?

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.

# Try and guess what (-10 +2)/2 is!

-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.

# What is (2 + 1)/(0 + 1)?

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.

# What is (2 -1)³?

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.

# What is the square root of 0?

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

# Do you know what the square root of -1 is?

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!

# Try and guess what (-2)² is!

(-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.

# Think you can figure out what 20% of 50 is?

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.

# What is 5% of 10?

.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.

# Can you figure out what 4² + 3² is?

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.

# What is 3³ + 1³?

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!

# Can you guess what 1,256,498 divided by 1 is?

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.

# 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 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.

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

# An item at a store costs \$20, but I have a coupon for 10% off. How much does the item cost now?

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.

# It's 9:00 now. What time will it be 3 hours and 14 minutes from now?

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.

# It's 3:30 now. What time was it one hour and 28 minutes ago?

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.

# Try and solve this problem: (2+2)² - (1-1)³

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.

# What is (√100)²?

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.

# What is √25 + √16?

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

# What is 7 times 7?

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

# What is the answer to this problem: (2³)/(2²)?

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.

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