Step-by-step Maths Level 5: Change from a total, and choosing the operation
Part of the Step-by-step Maths Level 5 perimeter of rectilinear shapes, time and money problems chapter. Chapter overview · whole chapter on one page
Change from a total, and choosing the operation
To find the change, first find the total of all the items. Then take the total from the money paid.
Key words help you choose: spent and left mean take away; altogether and total mean add.
Key ideas
- Find the total of all the items first.
- Change = money paid − total.
- Explain the operation with a reason from the story.
Method. Find the total of all the items, then take it from the money paid.
- Work out the cost of the cups. Multiply the price by the number of cups.3 × £1.25 = £3.75
- Add the cost of the cake. Add all the items to find the total.£3.75 + £2.40 = £6.15
- Work out the change. Change is what is left from the money paid.£10.00 - £6.15 = £3.85
- Write the answer. Give the change with the pound sign.£3.85
Check. Check: £6.15 + £3.85 = £10.00.
Watch out. Add all the items before you take anything away.
Method. Choose the operation from what happens in the story, and say why.
- Read the story. Money is spent, so some of it goes away.£15.00 spent £3.50
- Choose the operation. When an amount goes away, we take it away.Subtract
- Give the reason. The money left is what is left after the spending.Accept any answer that says subtract and gives a reason, such as: the money is taken away
Check. Accept any answer that names the operation and gives a sensible reason, such as the one shown.
Watch out. Read the key words: spent, left, altogether, total, change, and each.
Method. Choose the operation from what happens in the story, and say why.
- Read the story. Two costs are put together for a total.£12.00 and £4.50
- Choose the operation. When amounts are combined, we add them.Add
- Give the reason. The total is the sum of the amounts.Accept any answer that says add and gives a reason, such as: the costs are put together
Check. Accept any answer that names the operation and gives a sensible reason, such as the one shown.
Watch out. Read the key words: spent, left, altogether, total, change, and each.
Watch out
Watch out. Change is found by subtracting only after the total is worked out. Do not take one item away from the money paid.
Exam tip
Grown-up tip. Ask: “Is the money going away, or are we putting amounts together?” before the child calculates.
Exercise 9E Practice: change and choosing the operation
Non-calculatorMethod. Choose the operation from what happens in the story, and say why.
- Read the story. Two costs are put together for a total.£20.34 and £7.97
- Choose the operation. When amounts are combined, we add them.Add
- Give the reason. The total is the sum of the amounts.Accept any answer that says add and gives a reason, such as: the costs are put together
Check. Accept any answer that names the operation and gives a sensible reason, such as the one shown.
Watch out. Read the key words: spent, left, altogether, total, change, and each.
Method. Find the total of all the items, then take it from the money paid.
- Work out the cost of the cups. Multiply the price by the number of cups.3 × £1.31 = £3.93
- Add the cost of the cake. Add all the items to find the total.£3.93 + £2.23 = £6.16
- Work out the change. Change is what is left from the money paid.£10.00 - £6.16 = £3.84
- Write the answer. Give the change with the pound sign.£3.84
Check. Check: £6.16 + £3.84 = £10.00.
Watch out. Add all the items before you take anything away.
Method. Choose the operation from what happens in the story, and say why.
- Read the story. Money is spent, so some of it goes away.£28.80 spent £1.60
- Choose the operation. When an amount goes away, we take it away.Subtract
- Give the reason. The money left is what is left after the spending.Accept any answer that says subtract and gives a reason, such as: the money is taken away
Check. Accept any answer that names the operation and gives a sensible reason, such as the one shown.
Watch out. Read the key words: spent, left, altogether, total, change, and each.
Method. Find the total of all the items, then take it from the money paid.
- Work out the cost of the cups. Multiply the price by the number of cups.3 × £1.65 = £4.95
- Add the cost of the cake. Add all the items to find the total.£4.95 + £2.07 = £7.02
- Work out the change. Change is what is left from the money paid.£15.00 - £7.02 = £7.98
- Write the answer. Give the change with the pound sign.£7.98
Check. Check: £7.02 + £7.98 = £15.00.
Watch out. Add all the items before you take anything away.
Method. Find the total of all the items, then take it from the money paid.
- Work out the cost of the cups. Multiply the price by the number of cups.3 × £1.71 = £5.13
- Add the cost of the cake. Add all the items to find the total.£5.13 + £2.59 = £7.72
- Work out the change. Change is what is left from the money paid.£20.00 - £7.72 = £12.28
- Write the answer. Give the change with the pound sign.£12.28
Check. Check: £7.72 + £12.28 = £20.00.
Watch out. Add all the items before you take anything away.
Method. Find the total of all the items, then take it from the money paid.
- Work out the cost of the cups. Multiply the price by the number of cups.2 × £1.76 = £3.52
- Add the cost of the cake. Add all the items to find the total.£3.52 + £1.59 = £5.11
- Work out the change. Change is what is left from the money paid.£20.00 - £5.11 = £14.89
- Write the answer. Give the change with the pound sign.£14.89
Check. Check: £5.11 + £14.89 = £20.00.
Watch out. Add all the items before you take anything away.
Method. Find the total of all the items, then take it from the money paid.
- Work out the cost of the cups. Multiply the price by the number of cups.4 × £1.18 = £4.72
- Add the cost of the cake. Add all the items to find the total.£4.72 + £1.43 = £6.15
- Work out the change. Change is what is left from the money paid.£15.00 - £6.15 = £8.85
- Write the answer. Give the change with the pound sign.£8.85
Check. Check: £6.15 + £8.85 = £15.00.
Watch out. Add all the items before you take anything away.
Method. Choose the operation from what happens in the story, and say why.
- Read the story. Money is spent, so some of it goes away.£28.09 spent £2.94
- Choose the operation. When an amount goes away, we take it away.Subtract
- Give the reason. The money left is what is left after the spending.Accept any answer that says subtract and gives a reason, such as: the money is taken away
Check. Accept any answer that names the operation and gives a sensible reason, such as the one shown.
Watch out. Read the key words: spent, left, altogether, total, change, and each.
Method. Find the total of all the items, then take it from the money paid.
- Work out the cost of the cups. Multiply the price by the number of cups.4 × £1.47 = £5.88
- Add the cost of the cake. Add all the items to find the total.£5.88 + £1.41 = £7.29
- Work out the change. Change is what is left from the money paid.£15.00 - £7.29 = £7.71
- Write the answer. Give the change with the pound sign.£7.71
Check. Check: £7.29 + £7.71 = £15.00.
Watch out. Add all the items before you take anything away.
Method. Choose the operation from what happens in the story, and say why.
- Read the story. Two costs are put together for a total.£16.28 and £5.17
- Choose the operation. When amounts are combined, we add them.Add
- Give the reason. The total is the sum of the amounts.Accept any answer that says add and gives a reason, such as: the costs are put together
Check. Accept any answer that names the operation and gives a sensible reason, such as the one shown.
Watch out. Read the key words: spent, left, altogether, total, change, and each.
Method. Choose the operation from what happens in the story, and say why.
- Read the story. Money is spent, so some of it goes away.£25.76 spent £2.91
- Choose the operation. When an amount goes away, we take it away.Subtract
- Give the reason. The money left is what is left after the spending.Accept any answer that says subtract and gives a reason, such as: the money is taken away
Check. Accept any answer that names the operation and gives a sensible reason, such as the one shown.
Watch out. Read the key words: spent, left, altogether, total, change, and each.
Method. Choose the operation from what happens in the story, and say why.
- Read the story. Two costs are put together for a total.£26.57 and £3.63
- Choose the operation. When amounts are combined, we add them.Add
- Give the reason. The total is the sum of the amounts.Accept any answer that says add and gives a reason, such as: the costs are put together
Check. Accept any answer that names the operation and gives a sensible reason, such as the one shown.
Watch out. Read the key words: spent, left, altogether, total, change, and each.
Method. Find the total of all the items, then take it from the money paid.
- Work out the cost of the cups. Multiply the price by the number of cups.3 × £0.88 = £2.64
- Add the cost of the cake. Add all the items to find the total.£2.64 + £1.29 = £3.93
- Work out the change. Change is what is left from the money paid.£20.00 - £3.93 = £16.07
- Write the answer. Give the change with the pound sign.£16.07
Check. Check: £3.93 + £16.07 = £20.00.
Watch out. Add all the items before you take anything away.
Method. Choose the operation from what happens in the story, and say why.
- Read the story. Money is spent, so some of it goes away.£23.67 spent £5.93
- Choose the operation. When an amount goes away, we take it away.Subtract
- Give the reason. The money left is what is left after the spending.Accept any answer that says subtract and gives a reason, such as: the money is taken away
Check. Accept any answer that names the operation and gives a sensible reason, such as the one shown.
Watch out. Read the key words: spent, left, altogether, total, change, and each.
Method. Find the total of all the items, then take it from the money paid.
- Work out the cost of the cups. Multiply the price by the number of cups.2 × £1.23 = £2.46
- Add the cost of the cake. Add all the items to find the total.£2.46 + £2.25 = £4.71
- Work out the change. Change is what is left from the money paid.£15.00 - £4.71 = £10.29
- Write the answer. Give the change with the pound sign.£10.29
Check. Check: £4.71 + £10.29 = £15.00.
Watch out. Add all the items before you take anything away.
Method. Choose the operation from what happens in the story, and say why.
- Read the story. Money is spent, so some of it goes away.£13.88 spent £3.50
- Choose the operation. When an amount goes away, we take it away.Subtract
- Give the reason. The money left is what is left after the spending.Accept any answer that says subtract and gives a reason, such as: the money is taken away
Check. Accept any answer that names the operation and gives a sensible reason, such as the one shown.
Watch out. Read the key words: spent, left, altogether, total, change, and each.