Understand the rule first
The denominator names the size of each part. Use equivalent fractions when denominators differ, and divide by the denominator before multiplying by the numerator when finding a fraction of a quantity.
Compare, combine and find fractions by making the parts comparable.
The denominator names the size of each part. Use equivalent fractions when denominators differ, and divide by the denominator before multiplying by the numerator when finding a fraction of a quantity.
Adding denominators as well as numerators, such as writing 1/4 + 1/4 = 2/8.
Reusable method: Draw a quick bar when the relationship is hard to see.Multiply numerator and denominator by the same number.
Answer B: 6/10
3/5 × 2/2 = 6/10.
Quick method: Draw a quick bar when the relationship is hard to see.
Rewrite two thirds in sixths.
Answer D: 5/6
2/3 = 4/6, so 4/6 + 1/6 = 5/6.
Quick method: Draw a quick bar when the relationship is hard to see.
First find one eighth of 64.
Answer D: 24
64 ÷ 8 = 8, and 3 × 8 = 24.
Quick method: Draw a quick bar when the relationship is hard to see.
Use a common denominator of 12.
Answer B: 7/12
5/6 = 10/12 and 1/4 = 3/12, so the difference is 7/12.
Quick method: Draw a quick bar when the relationship is hard to see.
Express one fifth in tenths before subtracting.
Answer A: 1/2
1/5 = 2/10. Then 7/10 − 2/10 = 5/10 = 1/2.
Quick method: Draw a quick bar when the relationship is hard to see.
Find one fifth first.
Answer B: 27
45 ÷ 5 = 9, and 3 × 9 = 27.
Quick method: Draw a quick bar when the relationship is hard to see.
Rewrite one sixth in twelfths.
Answer C: 3/4
1/6 = 2/12, so 7/12 + 2/12 = 9/12 = 3/4.
Quick method: Draw a quick bar when the relationship is hard to see.
Compare using decimals or a common denominator.
Answer D: 7/10
5/8 = 0.625, 2/3 ≈ 0.667, 3/5 = 0.6 and 7/10 = 0.7, so 7/10 is greatest.
Quick method: Draw a quick bar when the relationship is hard to see.
Divide 3.6 by 12, then multiply by 5.
Answer A: 1.5 m
One twelfth of 3.6 m is 0.3 m; five twelfths is 5 × 0.3 = 1.5 m.
Quick method: Draw a quick bar when the relationship is hard to see.
After the morning, find two thirds of the amount left.
Answer B: 10/21
After the morning, 5/7 remains. Two thirds of that remains after the afternoon: 2/3 × 5/7 = 10/21.
Quick method: Draw a quick bar when the relationship is hard to see.