Year 6 Arithmetic (SATs): The unit method and percentages of a whole

Method. Find the cost of one cake, then multiply.

1. Find the amount for one unit. 12 is shared by 4 units.
   12 ÷ 4 = 3
2. Multiply by the number of units you want. There are 6 units to find.
   3 × 6 = 18
3. Write the answer.
   £18

Check. The cost of one cake is £3. ✓

Method. Find the cost of one cake, then multiply.

1. Find the amount for one unit. 15 is shared by 5 units.
   15 ÷ 5 = 3
2. Multiply by the number of units you want. There are 9 units to find.
   3 × 9 = 27
3. Write the answer.
   £27

Check. The cost of one cake is £3. ✓

Method. Find the cost of one cake, then multiply.

1. Find the amount for one unit. 9 is shared by 3 units.
   9 ÷ 3 = 3
2. Multiply by the number of units you want. There are 8 units to find.
   3 × 8 = 24
3. Write the answer.
   £24

Check. The cost of one cake is £3. ✓

Method. Find the cost of one cake, then multiply.

1. Find the amount for one unit. 24 is shared by 6 units.
   24 ÷ 6 = 4
2. Multiply by the number of units you want. There are 10 units to find.
   4 × 10 = 40
3. Write the answer.
   £40

Check. The cost of one cake is £4. ✓

Method. Divide 18 by 45, then multiply by 100.

1. Write the part as a fraction of the whole. 18 out of 45.
   18/45
2. Multiply by 100 to get a percentage. Percent means out of 100.
   18/45 × 100 = 40%
3. Write the answer.
   40%

Check. 18 ÷ 45 = 0.4, which is 40%. ✓

Method. Divide 12 by 80, then multiply by 100.

1. Write the part as a fraction of the whole. 12 out of 80.
   12/80
2. Multiply by 100 to get a percentage. Percent means out of 100.
   12/80 × 100 = 15%
3. Write the answer.
   15%

Check. 12 ÷ 80 = 0.15, which is 15%. ✓

Method. Divide 45 by 60, then multiply by 100.

1. Write the part as a fraction of the whole. 45 out of 60.
   45/60
2. Multiply by 100 to get a percentage. Percent means out of 100.
   45/60 × 100 = 75%
3. Write the answer.
   75%

Check. 45 ÷ 60 = 0.75, which is 75%. ✓

Method. Divide 14 by 40, then multiply by 100.

1. Write the part as a fraction of the whole. 14 out of 40.
   14/40
2. Multiply by 100 to get a percentage. Percent means out of 100.
   14/40 × 100 = 35%
3. Write the answer.
   35%

Check. 14 ÷ 40 = 0.35, which is 35%. ✓

Method. Find the cost of one pen, then multiply by 7.

1. Find the amount for one unit. 15 is shared by 3 units.
   15 ÷ 3 = 5
2. Multiply by the number of units you want. There are 7 units to find.
   5 × 7 = 35
3. Write the answer.
   £35

Check. £5 each, and 7 × £5 = £35. ✓

Method. Write the part as a fraction of the whole.

1. Write the part as a fraction of the whole. 150 out of 600.
   150/600
2. Multiply by 100 to get a percentage. Percent means out of 100.
   150/600 × 100 = 25%
3. Write the answer.
   25%

Check. 150 ÷ 600 = 0.25, which is 25%. ✓

Method. Find the price of one apple, then multiply by 4.

1. Find the amount for one unit. 360 is shared by 9 units.
   360 ÷ 9 = 40
2. Multiply by the number of units you want. There are 4 units to find.
   40 × 4 = 160
3. Write the answer.
   160p

Check. 40p each, and 4 × 40p = 160p. ✓

Method. Work out both amounts.

1. 25% of 80. 80 ÷ 4 = 20.
   20
2. 80% of 25. 25 × 80 ÷ 100 = 20.
   20
3. Write the answer.
   No

Check. Both are 20. ✓

Method. Divide 37 by 50, then multiply by 100.

1. Write the part as a fraction of the whole. 37 out of 50.
   37/50
2. Multiply by 100 to get a percentage. Percent means out of 100.
   37/50 × 100 = 74%
3. Write the answer.
   74%

Check. 37 ÷ 50 = 0.74, which is 74%. ✓

Method. Write the part left as a fraction of the whole.

1. Write the fraction. 60/80.
   60/80
2. Convert. 60 ÷ 80 = 0.75, which is 75%.
   75%
3. Write the answer.
   75%, because 60 out of 80 is 0.75.

Check. 75% of 80 is 60. ✓