NBT NBT Mathematics: Number Sense and Calculations 1 — Questions and Answers
Question 1: What is the least common multiple (LCM) of 12 and 18?
- 24
- 36 (Correct answer)
- 72
- 6
Correct answer: 36
The LCM of 12 and 18 is 36, the smallest number divisible by both 12 and 18.
Question 2: Which of the following is an irrational number?
- √16
- √9
- √25
- √7 (Correct answer)
Correct answer: √7
√7 cannot be expressed as a ratio of two integers since 7 is not a perfect square, making it irrational.
Question 3: What is the value of (−3)² − (−3)?
- 6
- 12 (Correct answer)
- 9
- 3
Correct answer: 12
(−3)² = 9, and subtracting −3 is the same as adding 3, giving 9 + 3 = 12.
Question 4: How many factors does 36 have?
- 7
- 8
- 9 (Correct answer)
- 6
Correct answer: 9
The factors of 36 are 1, 2, 3, 4, 6, 9, 12, 18, and 36, giving a total of 9 factors.
Question 5: Which of the following values is the greatest?
- −3/4
- −0.8
- −2/3
- −0.5 (Correct answer)
Correct answer: −0.5
−0.5 is closest to zero among these negative numbers, making it the greatest.
Question 6: What is the prime factorization of 180?
- 2² × 3² × 5 (Correct answer)
- 2 × 3² × 5²
- 2³ × 3 × 5
- 2² × 3 × 5²
Correct answer: 2² × 3² × 5
180 = 4 × 9 × 5 = 2² × 3² × 5, which is verified by multiplying back: 4 × 9 × 5 = 180.
Question 7: If p and q are both prime numbers greater than 2, which statement must always be true?
- p + q is prime
- p × q is even
- p + q is even (Correct answer)
- p − q is prime
Correct answer: p + q is even
All primes greater than 2 are odd, and the sum of two odd numbers is always even, so p + q must be even.
NBT NBT Mathematics: Number Sense and Calculations 1
What is the least common multiple (LCM) of 12 and 18?