The Mental Math Quiz

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

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

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

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

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

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.

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

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.

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

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

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

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

-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.

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.

-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.

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.

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.

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

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!

(-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.

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.

.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.

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.

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!

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.

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.

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

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.

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.

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.

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.

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.

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

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

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.