Rounding to 1 Significant Figure
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Learning Objective: I will learn… How to round to whole numbers , decimal places and significant figures. Key words: Square My Learning Outcome… Triangle I will apply my learning I will evaluate my trapezium by… learning by… Rounding . Explaining to your partner how to round to 1 significant figure? L7: Application Tasks… L4 Rounding to nearest 10 or 100. L5 Rounding to decimal places. L6 Rounding to significant figures. Be bale to understand standard form. Learn L4 Rounding – to the nearest 10 4832 No 5 or more? 4830 4837 Yes 5 or more? 4840 195 Yes 5 or more? 200 Apply 15823 5 or 1 No 5872 15820 0 Copy & 5900 Yes more? Your Turn L4 Rounding – to the nearest 100 Number complete this table: 89 5 or more? Yes 5 or more? 100 To nearest 10 37520 To nearest 100 37500 37 521 To nearest 1000 38000 274500 274500 274 503 275000 7630920 7630900 7631000 9880 450 9900 10000 500 0 7 630 918 9 875 452 Learn Rounding to 1 Decimal Place (1DP) 4.832 5 No 5 or 4.842 5 No 5 or 4.8 4.8 4.87 5.2671 4 Yes 5 or more? Yes 4.9 5 or more? more? 4.852 Yes 5 or more? 4.9 more? 5.3 L5 1.967 Yes 2.0 5 or more? Learn L5 Rounding to Decimal Places: 2DP 4.832 5 No 5 or 4.846 4.83 4.85 more? Yes 5 or more? more? 4.8 1.694 9 No 5 or 5.267 1 Yes 5 or 1.69 5.27 more? 4.8595 1 Yes 5 or 6 1.897 Yes more? 1.9 0 5 or more? Learn L5 Rounding to Decimal Places: 3DP 4.832 5 Yes 5 or 4.846 2 No 5 or 4.859 5 Yes 5 or 4.833 4.846 4.86 more? more? 1.694 2 No 5 or 5.262 7 Yes 5 or 1.694 5.263 more? more? 0 1.999 9 Yes 5 or more? more? 2.00 0 Rounding to Decimal Places Apply 4.852 5 or more? Yes 4.9 Your Turn 1DP 1.694 9 No 5 or more? 1.69 Copy & Number complete this table: 63.4721 D 2DP 5.262 7 Yes 5 or 3DP more? 5.263 To 1DP To 2DP To 3DP 63.5 63.47 63.472 87.6564 87.7 87.66 87.656 149.9875 150.0 149.99 149.988 3.54029 3.5 3.54 3.540 0.59999 0.6 0.60 0.600 L6 Learn Significant Figures: Important Zeros in Numbers a. 5 2 0 0 0 b. 5 . 2 0 0 c. 0 . 0 5 0 d. 0 2 . 5 0 Which zeros matter? Are there any we could get rid of and still have the same value? When dealing with Significant Figures, you need to keep any zeros that tell us the value of a number Learn Rounding to 1 Significant Figure (1SF) 0.076 5 Yes 5 or 0.001 2 No 5 or 0.08 0.001 more? 241 No L6 5 or more? 200 more? 587 Yes 5 or more? 600 1.009 5 No 5 or more? 1 75 Yes 5 or more? 80 Learn Rounding to 2 Significant Figure (2SF) 1472 Yes 5 or more? 1500 42728 Yes L6 5 or more? 43000 1.427 9 No 5 or 0.053 5 Yes 5 or more? more? 1.4 0.05 20447 8 No 5 or 4 0.069 6 Yes 5 or more? more? 200000 0.07 0 Learn Rounding to 3 Significant Figure (3SF) 0.0267 1 No 5 or 3.294 9 No 5 or 0.026 7 13798 3.29 more? Yes L6 5 or more? 13800 34728 No more? 5 or more? 3470 97497 8 Yes 5 or more? 975000 0 12.06 9 Yes 5 or more? 12.1 Rounding to Significant Figures Apply 0.076 5 Yes 5 or 1SF 2SF 42728 more? Your Turn 0.08 more? 43000 Copy & Number complete 6.3528 this table: C 5 or more? Yes 12.06 9 Yes 5 or To 1SF 3SF 12.1 To 2SF To 3SF 6.35 6.4 6 34.026 34.0 34 30 0.005708 0.00571 0.0057 0.006 150.932 151 150 200 0.0000783 5 0.0000784 0.000078 0.00008 You need to understand about powers of Learn 10. Try these to test your previous knowledge. 10-1 102 101 106 105 103 10-2 10-3 Remember this? 104 100 se the worksheet “powers of ten” for further explanation Learn Standard Form is used a lot in maths and science as a convenient way of writing very large, or very small numbers for example: The distance from the earth to the sun is 149 000 000 km huge! A hydrogen atom has a diameter of about 0.000 000 2 mm microscopic! Learn Let’s deal with large numbers first. Look at how these numbers have been broken dow 500 = 5 × 100 = 5 × 102 5000 = 5 × 1 000 = 5 × 103 50 000 = 5 × 10 000 = 5 × 104 you know how to write these as powers of 10 Learn What about these? = 5.5 × 102 550 = 5.5 × 100 5 500 = 5.5 × 1 000 = 5.5 × 103 4 = 5.5 × 10 000 = 5.5 × 10 55 000 Learn Put these numbers into standard form: 6 000 400 80 000 9 000 =6× 103 4 000 = 4 × 103 = 4× 102 450 = 8× 104 = 9 × 103 4 00 000 = 4 × 105 = 4.5 × 102 = 5.5 × 104 55000 3500 = 3.5 × 103 750 000= 7.5 × 105 Learn Standard form is: a number between 1 and 10 × a power of ten Apply Now try writing these numbers in standard form 5 000 000 = 5 × 106 5 500 000 = 5.5 × 106 5 250 000 = 5.25 × 106 5 100 000 = 5.1 × 106 5 156 342 = 5.156342 × 106 Learn Reverse! Change each of these numbers to an ordinary number 6× 102 2.8 × 101 2× 103 9.9 × 1010 5× 107 7.1 × 104 9× 108 3.97 × 102 3.7 × 109 8.172 × 102 Learn The next stage is to write very small numbers, i.e. numbers less than 1 Check that you understand about negative powers of 10 0.001 = 0.1 = 1 = 10-1 10 0.00001 = 0.01 = 0.0001 = Apply Write in standard form: 0.007 0.006 7 0.04 0.000 000 002 34 0.000 000 005 0.006 7 0.0234 0.3 0.000 002 3 0.000 045 * 3.5 × 10-1 4.5 × 10-4 7.2 × 10-5 6.1 × 10-3 1.17 × 10-10 Apply Change each of these to a large or small number: 5.5 × 10-6 1.115 × 104 6.5 × 10-8 1.412 × 10-3 3.2 × 105 7.2 × 101 2.9 × 102 9.01 × 10-2 3.167 × 10-11 1.17 × 106 Apply * How do you round to the nearest Significant figure? *
