4. ES: Application of Number: Decimal Numbers

AON: Decimals

1. Decimals Application of Number Unit 1 Leigh McQuaid

2. Learning Intentions Round answers to a number of decimal places Order decimals using knowledge of place value Carry out calculations with decimals in the context of money.

3. Place Value 7 6 5 4 3 2 1

4. Place Value with decimals 4 2 1 3 2 1 3 Units / ones Tens Hundreds Thousands Tenths Hundredths Thousandths

5. What are decimals? Decimals are in between whole numbers: We must consider the place value of our decimals so that we can order them (Remember thousandths are smaller than hundredths!) The closest number to the decimal point has the biggest value.

6. What are decimals? There is an infinite number of decimals between each whole number Place value and ordering decimals - Decimals - AQA - GCSE Maths Revision - AQA - BBC Bitesize

7. Bigger or Smaller? There is an infinite number of decimals between each whole number Ten thousands thousands hundreds tens units 1/10 1/100 1/1000 1 1 Ten thousands thousands hundreds tens units 1/10 1/100 1/1000 1 8

8. Bigger or Smaller? Decide which number is bigger or smaller, using your knowledge of place value. (Answers at the end) Ten thousands thousands hundreds tens units 1/10 1/100 1/1000 3 1 2 Ten thousands thousands hundreds tens units 1/10 1/100 1/1000 3 8

9. Bigger or Smaller? Decide which number is bigger or smaller, using your knowledge of place value. Ten thousands thousands hundreds tens units 1/10 1/100 1/1000 2 5 5 7 Ten thousands thousands hundreds tens units 1/10 1/100 1/1000 2 5 8

10. Bigger or Smaller? Ten thousands thousands hundreds tens units 1/10 1/100 1/1000 1 6 2 1 5 Ten thousands thousands hundreds tens units 1/10 1/100 1/1000 1 6 2 9 Decide which number is bigger or smaller, using your knowledge of place value.

11. Ordering decimals Look at each of the decimals you are ordering and how many numbers there are after the decimal point. If there is not the same amount, insert zeros at the end to make them the same. Now ignore the decimal point and imagine as whole numbers . Order these ‘whole numbers’ now. For example- Order the following decimals in ascending order: a) 0.91, 0.2, 0.6, 0.3          b) 0.314, 1.2, 0.98, 1.06 c) 6.24, 8.184, 7.426, 4.109 0.91, 0.20, 0.60, 0.30 0.314, 1.200, 0.980, 1.060 6.240, 8.184, 7.426, 4.109

12. Rounding Decimals Rounding decimals is the same as rounding whole numbers, look at the digit next to it to decide whether to round up or down. (Answers at the end) Ten thousands thousands hundreds tens units 1/10 1/100 1/1000 1 1 2 Ten thousands thousands hundreds tens units 1/10 1/100 1/1000 1 1 9

13. Rounding Decimals to 1d.p When rounding to 1 decimal place, look at the 2nd digit after the decimal point Ten thousands thousands hundreds tens units 1/10 1/100 1/1000 3 1 2 Ten thousands thousands hundreds tens units 1/10 1/100 1/1000 3 8

14. Rounding Decimals to 1d.p When rounding to 1 decimal place, look at the 2nd digit after the decimal point Ten thousands thousands hundreds tens units 1/10 1/100 1/1000 2 5 5 7 Ten thousands thousands hundreds tens units 1/10 1/100 1/1000 2 5 8 2

15. Rounding Decimals to 2d.p When rounding to 2 decimal places, look at the 3rd digit after the decimal point. The first digit will stay the same. Ten thousands thousands hundreds tens units 1/10 1/100 1/1000 1 6 2 5 5 Ten thousands thousands hundreds tens units 1/10 1/100 1/1000 1 6 2 5 1

16. Rounding Decimals to 2d.p When rounding to 2 decimal places, look at the 3rd digit after the decimal point. The first digit will stay the same. Ten thousands thousands hundreds tens units 1/10 1/100 1/1000 3 9 3 7 8 2 Ten thousands thousands hundreds tens units 1/10 1/100 1/1000 3 9 3 7 8 8

17. Rounding Decimals to 2d.p When rounding to 2 decimal places, look at the 3rd digit after the decimal point. The first digit will stay the same. Ten thousands thousands hundreds tens units 1/10 1/100 1/1000 4 2 1 1 2 Ten thousands thousands hundreds tens units 1/10 1/100 1/1000 4 2 1 1 6

18. Complete the Rounding Code Breaker

19. Decimals in Money contexts In the context of money, there must always be 2 numbers after the decimal point. You may need to round answers to 2 decimal points or add in a 0 to make the two digits, for example: If one tint brush costs £9.90, how much will 5 tint brushes cost? A stylist carries out a perm on 3 clients and the total comes to £231.90, what is the average cost of each perm? A group of 5 friends each order a cocktail and the total comes to £51.78. If they want to split the bill evenly, how much will each friend have to pay?

20. Learning Intentions Round answers to a number of decimal places Order decimals using knowledge of place value Carry out calculations with decimals in the context of money.

21. ANSWErs

22. 1.1 is less than 1.8 3.12 is greater than 3.08 25.57 is less than 25.8 162.015 is greater than 162.009 0.2, 0.3, 0.6, 0.91 0.314, 0.98, 1.06, 1.2 4.109, 6.24, 7.426, 8.184