Math Number Sense and Operations 4 — Questions and Answers
Question 1: Which of the following is an irrational number?
- √16
- √9
- √2 (Correct answer)
- √25
Correct answer: √2
√2 cannot be expressed as a fraction of two integers, making it irrational.
Question 2: What is the least common multiple (LCM) of 8 and 12?
- 4
- 24 (Correct answer)
- 48
- 96
Correct answer: 24
The LCM of 8 and 12 is 24, the smallest number divisible by both.
Question 3: A store sells juice in 3/4-liter bottles. How many bottles are needed to fill a 6-liter container?
- 6
- 7
- 8 (Correct answer)
- 9
Correct answer: 8
6 ÷ 3/4 = 6 × 4/3 = 8 bottles.
Question 4: What is the value of 2^5 × 2^3?
- 2^8 (Correct answer)
- 2^15
- 4^8
- 2^2
Correct answer: 2^8
When multiplying powers with the same base, add the exponents: 2^(5+3) = 2^8.
Question 5: Which number is a perfect square?
- 50
- 72
- 81 (Correct answer)
- 90
Correct answer: 81
81 = 9², so it is a perfect square; the others have no integer square roots.
Question 6: Express 0.000047 in scientific notation.
- 4.7 × 10^-5 (Correct answer)
- 47 × 10^-6
- 4.7 × 10^5
- 0.47 × 10^-4
Correct answer: 4.7 × 10^-5
Moving the decimal 5 places right gives 4.7, so the notation is 4.7 × 10^-5.
Question 7: Which set of numbers is ordered from least to greatest?
- -3, -1, 0, 2 (Correct answer)
- 2, 0, -1, -3
- -1, -3, 0, 2
- 0, -1, 2, -3
Correct answer: -3, -1, 0, 2
On a number line, -3 < -1 < 0 < 2, so -3, -1, 0, 2 is the correct order.
Math Number Sense and Operations 4
Which of the following is an irrational number?