Year 6 Arithmetic (SATs): Sharing and grouping in a ratio
Part of the Year 6 Arithmetic (SATs) ratio and proportion chapter. Chapter overview · whole chapter on one page
Sharing and grouping in a ratio
Rule
To share in a ratio, add the parts, find the value of one part, then multiply each number in the ratio by that value.
Check the shares add up to the total. With three friends, add all three parts of the ratio.
Key ideas
- Share in a ratio by finding the value of one part.
- The total must be shared into all the parts of the ratio.
- The shares must add up to the total.
Method. Find the total parts, the value of one part, then each share.
- Add the parts of the ratio. 2 + 3 = 5, so the total is shared into 5 equal parts.2 + 3 = 5 parts
- Find the value of one part. Share the total into 5 equal parts.60 ÷ 5 = 12
- Find each share. Multiply the value of one part by each number in the ratio.2 × 12 = 24 and 3 × 12 = 36
- Write the answer. Ali £24, Ben £36
Check. £24 + £36 = £60. ✓
Method. Find one part by dividing by 7.
- Add the parts of the ratio. 3 + 4 = 7, so the total is shared into 7 equal parts.3 + 4 = 7 parts
- Find the value of one part. Share the total into 7 equal parts.84 ÷ 7 = 12
- Find each share. Multiply the value of one part by each number in the ratio.3 × 12 = 36 and 4 × 12 = 48
- Write the answer. 36 and 48
Check. 36 + 48 = 84. ✓
Method. Add all three parts, then find the value of one part.
- Add the parts. 2 + 3 + 5 = 10 parts.10 parts
- Find one part. 120 ÷ 10 = 12.12
- Find the 5-part share. 5 × 12 = 60.60
- Write the answer. 60
Check. 24 + 36 + 60 = 120. ✓
Exercise 5C Practice: sharing and grouping in a ratio
Non-calculatorMethod. Find the total parts, the value of one part, then each share.
- Add the parts of the ratio. 1 + 3 = 4, so the total is shared into 4 equal parts.1 + 3 = 4 parts
- Find the value of one part. Share the total into 4 equal parts.48 ÷ 4 = 12
- Find each share. Multiply the value of one part by each number in the ratio.1 × 12 = 12 and 3 × 12 = 36
- Write the answer. 12 and 36
Check. 12 + 36 = 48. ✓
Method. Find the total parts, the value of one part, then each share.
- Add the parts of the ratio. 2 + 3 = 5, so the total is shared into 5 equal parts.2 + 3 = 5 parts
- Find the value of one part. Share the total into 5 equal parts.75 ÷ 5 = 15
- Find each share. Multiply the value of one part by each number in the ratio.2 × 15 = 30 and 3 × 15 = 45
- Write the answer. 30 and 45
Check. 30 + 45 = 75. ✓
Method. Find the total parts, the value of one part, then each share.
- Add the parts of the ratio. 4 + 5 = 9, so the total is shared into 9 equal parts.4 + 5 = 9 parts
- Find the value of one part. Share the total into 9 equal parts.90 ÷ 9 = 10
- Find each share. Multiply the value of one part by each number in the ratio.4 × 10 = 40 and 5 × 10 = 50
- Write the answer. 40 and 50
Check. 40 + 50 = 90. ✓
Method. Find the total parts, the value of one part, then each share.
- Add the parts of the ratio. 3 + 5 = 8, so the total is shared into 8 equal parts.3 + 5 = 8 parts
- Find the value of one part. Share the total into 8 equal parts.120 ÷ 8 = 15
- Find each share. Multiply the value of one part by each number in the ratio.3 × 15 = 45 and 5 × 15 = 75
- Write the answer. 45 and 75
Check. 45 + 75 = 120. ✓
Method. Find the total parts, the value of one part, then each share.
- Add the parts of the ratio. 4 + 5 = 9, so the total is shared into 9 equal parts.4 + 5 = 9 parts
- Find the value of one part. Share the total into 9 equal parts.63 ÷ 9 = 7
- Find each share. Multiply the value of one part by each number in the ratio.4 × 7 = 28 and 5 × 7 = 35
- Write the answer. 28 and 35
Check. 28 + 35 = 63. ✓
Method. Find the total parts, the value of one part, then each share.
- Add the parts of the ratio. 1 + 8 = 9, so the total is shared into 9 equal parts.1 + 8 = 9 parts
- Find the value of one part. Share the total into 9 equal parts.54 ÷ 9 = 6
- Find each share. Multiply the value of one part by each number in the ratio.1 × 6 = 6 and 8 × 6 = 48
- Write the answer. 6 and 48
Check. 6 + 48 = 54. ✓
Method. Find the total parts, then the value of one part.
- Add the parts of the ratio. 2 + 3 = 5, so the total is shared into 5 equal parts.2 + 3 = 5 parts
- Find the value of one part. Share the total into 5 equal parts.25 ÷ 5 = 5
- Find each share. Multiply the value of one part by each number in the ratio.2 × 5 = 10 and 3 × 5 = 15
- Write the answer. 10 and 15
Check. 10 + 15 = 25. ✓
Method. Share £250 into 5 parts.
- Add the parts of the ratio. 3 + 2 = 5, so the total is shared into 5 equal parts.3 + 2 = 5 parts
- Find the value of one part. Share the total into 5 equal parts.250 ÷ 5 = 50
- Find each share. Multiply the value of one part by each number in the ratio.3 × 50 = 150 and 2 × 50 = 100
- Write the answer. £150
Check. £150 + £100 = £250. ✓
Method. Share the counters in the ratio 5 : 7.
- Add the parts of the ratio. 5 + 7 = 12, so the total is shared into 12 equal parts.5 + 7 = 12 parts
- Find the value of one part. Share the total into 12 equal parts.96 ÷ 12 = 8
- Find each share. Multiply the value of one part by each number in the ratio.5 × 8 = 40 and 7 × 8 = 56
- Write the answer. 40
Check. 40 red and 56 blue make 96. ✓
Method. Add the parts and find one part.
- Add the parts. 2 + 3 + 5 = 10.10
- Find one part. 120 ÷ 10 = 12.12
- Find the 2-part share. 2 × 12 = 24.24
- Write the answer. 24
Check. The three shares are 24, 36 and 60. ✓
Method. Add the parts, find one part, then the largest share.
- Add the parts. 1 + 2 + 3 = 6.6
- Find one part. 36 ÷ 6 = 6.6
- Find the largest share. 3 × 6 = 18.18
- Write the answer. 18
Check. 6 + 12 + 18 = 36. ✓
Method. Find the value of one part.
- Add the parts. 3 + 2 = 5.5
- Find one part. 40 ÷ 5 = 8.8
- Find the shares. 3 × 8 = 24 and 2 × 8 = 16.24 and 16
- Write the answer. No, the shares are 24 and 16, because the 3 parts get 24 and the 2 parts get 16.
Check. 24 + 16 = 40, so 20 and 20 is not in the ratio 3 : 2. ✓
Method. Share 72 in the ratio 1 : 2.
- Add the parts of the ratio. 1 + 2 = 3, so the total is shared into 3 equal parts.1 + 2 = 3 parts
- Find the value of one part. Share the total into 3 equal parts.72 ÷ 3 = 24
- Find each share. Multiply the value of one part by each number in the ratio.1 × 24 = 24 and 2 × 24 = 48
- Write the answer. 48
Check. 24 + 48 = 72. ✓