Divide 12 into 4 equal groups: 12 ÷ 4 = 3 per group. Then take 3 groups: 3 × 3 = 9. A common error is stopping after finding 1/4 of 12 (which is 3) and giving 3 as the final answer, ignoring the numerator.
Question 2 True / False
To find 2/5 of 15, you divide 15 by 2, then multiply by 5.
TTrue
FFalse
Answer: False
The denominator tells you how many equal groups to make; the numerator tells you how many groups to take. You divide by the denominator (5): 15 ÷ 5 = 3, then multiply by the numerator (2): 3 × 2 = 6. Swapping the roles of numerator and denominator is a very common error.
Question 3 Short Answer
A bag has 20 marbles. You want to find 3/4 of the marbles. Describe the two steps and give the answer.
Think about your answer, then reveal below.
Model answer: Divide 20 by 4 to find one equal group (5 marbles), then multiply by 3 to take 3 of those groups: 5 × 3 = 15 marbles.
The denominator 4 means split 20 into 4 equal groups of 5. The numerator 3 means take 3 of those groups. This divide-then-multiply process is the core procedure for any fraction of a set.