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Year 7

Securing understanding of arithmetic procedures with integers and decimals

I can add, subtract, multiply and divide with integers and decimals using a calculator to check.

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New
New
Year 7

Securing understanding of arithmetic procedures with integers and decimals

I can add, subtract, multiply and divide with integers and decimals using a calculator to check.

Download all resources
Share activities with pupils

Lesson details

Key learning points

  1. The decimal point determines the place value of each digit.
  2. A calculator needs the decimal point to determine the place value of each digit.
  3. A calculator produces the correct answer for the values inputted.
  4. The answer can be checked to see if it appears too big or too small.

Common misconception

The assumption that if the calculator gives an answer then it must be correct!

It is really important to encourage pupils to both check calculator inputs carefully and consider the reasonableness of their answers.

Keywords

  • Decimal form - A number is in decimal form when the decimal point is shown and there are digits to the right of the decimal point.

As an extension to task you could get pupils to come up with their own 'splat' questions. This will give them the opportunity to really think about what information is required to consider the magnitude of an answer.
Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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Starter quiz

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6 Questions

Q1.
Select all the integers.
Correct answer: 36
3.6
0.36
Correct answer: 360
Q2.
Work out: 259 + 834 =
Correct Answer: 1093
Q3.
Match each symbol with the correct digit to complete the calculation.
An image in a quiz
Correct Answer:Triangle,2

2

Correct Answer:Square,6

6

Correct Answer:Hexagon,4

4

Q4.
Match each operation on the left to the equivalent operations on the right.
Correct Answer:$$\times4$$,$$\times2 \times2$$

$$\times2 \times2$$

Correct Answer:$$\times8$$,$$\times2 \times2\times2$$

$$\times2 \times2\times2$$

Correct Answer:$$\div9$$,$$\div 3 \div 3$$

$$\div 3 \div 3$$

Correct Answer:$$\div6$$,$$\div 2 \div 3$$

$$\div 2 \div 3$$

Correct Answer:$$\div5$$,$$\div 10 \times 2$$

$$\div 10 \times 2$$

Q5.
Sam buys 6 boxes of chocolates. Each box costs £4.85. What is the total cost of the chocolates?
£19.40
£24.25
Correct answer: £29.10
£38.80
Q6.
Five Oak students buy a pizza together. The pizza costs £15.80. They share the cost equally. How much should each student pay? £
Correct Answer: 3.16, £3.16

Exit quiz

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6 Questions

Q1.
A number is in decimal form when the decimal point is shown and there are to the right of the decimal point.
Correct Answer: digits, digit
Q2.
Four students work out the answer to £496 200 + £35 900. Only one student is right. Without using a calculator, select the student who is correct.
Laura: £496 559
Correct answer: Lucas: £532 100
Sam: £40 862
Sofia: £855 200
Q3.
Select the number that is closest to the answer to the calculation 37 143 − 8786.
28
280
2800
Correct answer: 28 000
280 000
Q4.
A pen costs £3.75. Use your calculator to work out the cost of 50 pens.
$${£375}\over{2}$$
£18.75
Correct answer: £187.50
$${£18.75}\over{4}$$
Q5.
A café sells coffee for £2.89, hot chocolate for £2.20 and flapjacks for 85p. Work out the cost of 3 coffees, 2 hot chocolates and 5 flapjacks.
£16.63
Correct answer: £17.32
£55.57
£438.07
Q6.
A banana costs 32p, a bunch of grapes costs £3.65 and a bag of apples costs £1.99. Lucas buys 8 bananas, 2 bunches of grapes and 2 bags of apples. How much change should he get from £20? £
Correct Answer: 6.16, £6.16, 616p, 616 p