ERB Mathematical Reasoning 1 — Questions and Answers
Question 1: On the ERB ISEE math section, what does 'estimation' most commonly require students to do?
- Find the exact answer
- Find an approximate answer close to the actual value (Correct answer)
- Use a calculator
- Convert units
Correct answer: Find an approximate answer close to the actual value
Estimation involves finding an approximate answer that is reasonably close to the exact value, useful when exact computation is not required.
Question 2: Which property states that a × (b + c) = a × b + a × c?
- Commutative property
- Associative property
- Distributive property (Correct answer)
- Identity property
Correct answer: Distributive property
The distributive property states that multiplying a number by a sum equals multiplying by each addend separately and then adding the results.
Question 3: What is the value of 3³ (3 to the power of 3)?
- 6
- 9
- 27 (Correct answer)
- 81
Correct answer: 27
3³ means 3 × 3 × 3 = 27, since the exponent indicates how many times the base is multiplied by itself.
Question 4: On the ERB math section, if a ratio of boys to girls is 3:5 and there are 24 boys, how many girls are there?
- 30
- 40 (Correct answer)
- 35
- 45
Correct answer: 40
If 3 parts = 24 boys, then 1 part = 8, so 5 parts = 40 girls.
Question 5: Which of the following is a prime number?
- 9
- 15
- 17 (Correct answer)
- 21
Correct answer: 17
17 is a prime number because it has no factors other than 1 and itself.
Question 6: What is 15% of 200?
- 25
- 30 (Correct answer)
- 35
- 40
Correct answer: 30
15% of 200 = 0.15 × 200 = 30.
ERB Mathematical Reasoning 1
On the ERB ISEE math section, what does 'estimation' most commonly require students to do?