Functional Skills Maths ROUNDING Approximate by rounding to

Functional Skills Maths ROUNDING Approximate by rounding to a whole number or to one or two decimal places Iain Blackshaw 1

Learning Objectives Your aim is to be able to: • Round to the nearest whole number, 10, 100 and 2 decimal places • Approximate whole numbers by rounding • Identify and round to a given number of significant figures 2

Rounding – to the nearest 10 4 8 3 7 4 8 3 2 No 4 8 3 0 5 or more? Yes 4 8 4 0 1 9 5 5 or more? Yes 5 or more? 2 0 0 3

Rounding – to the nearest 100 1 5 8 2 3 1 No 5 or more? 1 5 8 2 0 0 5 8 7 2 Yes 5 or more? 5 9 0 0 8 9 Yes 5 or more? 1 0 0 4

Try these questions Round the following numbers to the nearest 100 13 = 140 23 = 260 18 = 180 98 345 4368 134 352 6500 192 985 9500 372 1050 1243 6929 5253 8728 37546 12425 Round the following numbers to the nearest 1000 2300 1978 13483 49268 123436 15500 999501 5

Answers Round the following numbers to the nearest 100 13 = 10 140 = 100 23 = 20 260 = 300 18 = 20 180 = 200 98 = 100 345 = 300 134 = 130 352 = 400 192 = 190 985 = 1000 372 = 370 1050 =1100 1243 = 1240 6929 = 6900 5253 = 5250 8728 = 8700 37546 = 37550 12425 = 12400 Round the following numbers to the nearest 1000 2300 = 2000 1978 = 2000 4368 = 4000 6500 = 7000 9500 = 10, 000 13483 = 13, 000 49268 = 49, 000 123436 = 123, 000 15500 = 16000 999501 = 1, 000 6

Complete the table Remember to go back to the original number each time before rounding Number To nearest 10 100 To nearest 1000 37 521 274 503 7 630 918 9 875 452 7

Answers Number To nearest 10 100 To nearest 1000 37 521 37520 37 500 38 000 274 503 274 500 275 000 7 630 918 7 630 920 7 630 900 7 631 000 9 875 9 880 9900 10 000 452 450 500 0 8

Rounding to Decimal Places: 2 DP 4. 8 3 2 5 No 5 or more? 4. 8 4 6 Yes 5 or more? 4. 8 3 4. 8 5 1. 6 9 4 9 5. 2 6 7 1 No 1. 6 9 5 or more? Yes 5. 2 7 4. 8 5 9 5 1 Yes 5 or more? 4. 8 6 5 or more? 1. 8 9 7 Yes 5 or more? 1. 9 0 9

Rounding to Decimal Places: 3 DP 4. 8 3 2 5 Yes 5 or more? 4. 8 4 6 2 No 5 or more? 4. 8 3 3 4. 8 4 6 1. 6 9 4 2 5. 2 6 2 7 No 5 or more? 1. 6 9 4 Yes 5 or more? 5. 2 6 3 4. 8 5 9 5 Yes 5 or more? 4. 8 6 0 1. 9 9 Yes 5 or more? 2. 0 0 0 10

Rounding to Decimal Places 4. 8 5 2 Yes 5 or more? 4. 9 Complete the tables Round the following numbers to 1 decimal places 6. 78 6. 8 4. 93 5. 03 2. 68 7. 55 3. 44 12. 09 18. 89 44. 347 82. 383 49. 2532 1 DP 1. 6 9 4 9 No 1. 6 9 Round the following numbers to 2 decimal places 3. 7854 3. 79 4. 5564 1. 595 6. 473 0. 273 2. 571 8. 995 0. 425 5. 721 325. 1741 82. 3643 2 DP 5 or more? 5. 2 6 2 7 Yes 3 DP 5 or more? 5. 2 6 3 Round the following numbers to The nearest whole number 23. 6798 24 63. 4721 87. 6564 149. 9875 3. 54029 0. 59999 0. 39999 0. 189 11

Answers Round the following numbers to 1 decimal places 2 decimal places The nearest whole number 6. 78 6. 8 4. 93 4. 9 5. 03 5. 0 2. 68 2. 7 7. 55 7. 6 3. 44 3. 4 12. 09 12. 1 18. 89 18. 9 44. 347 44. 3 82. 383 82. 4 49. 2532 49. 3 3. 7854 4. 5564 1. 595 6. 473 0. 273 2. 571 8. 995 0. 425 5. 721 325. 1741 82. 3643 3. 79 4. 56 1. 60 6. 47 0. 27 2. 57 9. 00 0. 43 5. 72 325. 17 82. 36 23. 6798 24 63. 4721 63 87. 6564 88 149. 9875 150 3. 54029 4 0. 59999 1 0. 39999 0 0. 189 0 12

FINAL CHALLENGE Now, you are getting familiar with how to round numbers effectively, take a look at the A-mazing Rounding Challenge on the additional document. Print it off and use a different colour pen/pencil to navigate your way from START to FINISH. How long will it take you to complete? GOOD LUCK! 13