Transcript Rounding
Rounding Intro 63.91 to Nearest Whole Number Nearest Whole Number Nearest Ten Nearest Hundred To 1 Decimal Place Rounding By Interactive Example Rounding Seven Questions Rounding When you use a tape measure to work out the length of a table often you give the answer to the nearest cm. This is known as ROUNDING You are often asked to ROUND an answer that you get on a calculator. What is 63.91 to the nearest Whole Number 63.0 63.1 63.2 63.3 63.4 63.5 63.6 63.7 63.8 63.9 0 1 2 3 4 5 6 7 8 9 63.98 63.99 The “scale” shows numbers between 63 and 64. 64.0 Where is 63.91 63.90 63.91 63.92 63.93 63.94 63.95 63.96 63.97 Can you see that 63.91 is closer to 64.0 64.00 Rounding 63.91 to a Whole Number What is 63.91 to the nearest Whole Number 63.0 63.1 63.2 63.3 63.4 63.5 63.6 63.7 63.8 63.9 0 1 2 3 4 5 6 7 8 9 A What two WHOLE numbers is 63.91 between 63 and 64 B What is the figure after 63 9 64.0 9 is called the ROUND FIGURE The scale can be split into TEN sections using the ROUND FIGURE If Round Figure is 01234 ROUND to 63 If Round Figure is 56789 ROUND to 64 Answer 64 Round 15.5 to nearest Whole Number 15.5 to nearest whole number is 16 1 5 . 5 Hide the decimal part to get LOW 15 Step 1 What is LOW 5 Step 2 Next Figure is Round Figure 1 5 . Whole number Round Figure Step 3 If the Round figure is 0 or 1 or 2 or 3 or 4 then round to LOW Sep 4 The Round figure is 5 or 6 or 7 or 8 or 9 so round to High After 15 is 16 ROUND to 16 5 No! Round 28.3 to Nearest whole number 28.3 to nearest whole number is 28 2 8 . 3 Hide the decimal part to get LOW 28 Step 1 What is LOW Step 2 Next Figure is Round Figure 3 2 8 . Whole number Round Figure Step 3 If the Round figure is 0 or 1 or 2 or 3 or 4 then round to LOW ROUND to 28 3 Yes! Round 89 to nearest Ten 89 to nearest Ten 90 8 9 10, 20, 30 ….. Must end in a 0 ….. Figure before Units Plus 0 80 Step 1 What is LOW 8 9 0 Step 2 Above 1st 0 is Round Figure 9 Round Figure Step 3 If the Round figure is 0 or 1 or 2 or 3 or 4 then round to LOW Step 4 The Round figure is 5 or 6 or 7 or 8 or 9 so round to High 90 80 + 10 is ROUND to 90 No! Round 324 to nearest Ten 324 to nearest Ten 320 3 2 4 10, 20, 30 ….. Must end in a 0 ….. Figure before Units Plus 0 320 Step 1 What is LOW 3 2 4 0 Step 2 1st Figure to be replaced is Round Figure 4 Round Figure Step 3 If the Round figure is 0 or 1 or 2 or 3 or 4 then round to LOW ROUND to 320 Yes! Round 1995 to nearest Hundred 1995 to nearest Hundred 200 1 9 9 5 100, 200, 300 ….. Must end in a 00 ….. Figure before Tens Plus 00 Step 1 What is LOW Step 2 Above 1st 0 is Round Figure 1900 9 1 9 9 5 0 0 Round Figure Step 3 If the Round figure is 0 or 1 or 2 or 3 or 4 then round to LOW Step 4 The Round figure is 5 or 6 or 7 or 8 or 9 so round to High 2000 1900 + 100 is ROUND to 2000 No! Round 9.95 to 1 Decimal Place 9.95 to 1dp is 10.0 9 . 9 5 Cover number then move to the right until there is one figure after the point 9.9 Step 1 What is LOW 9 . 9 5 1dp 5 Step 2 Next Figure is Round Figure Round Figure Step 3 If the Round figure is 0 or 1 or 2 or 3 or 4 then round to LOW Step 4 The Round figure is 5 or 6 or 7 or 8 or 9 so round to High After 9.9 is 10.0 ROUND to 10.0 No! Round 8.832 to 1 Decimal Place 7.832 to 1dp is 7.8 7 . 8 2 3 Cover number then move to the right until there is one figure after the point 7.8 Step 1 What is LOW 7 . 8 1dp Step 2 Next Figure is Round Figure 3 Round Figure Step 3 If the Round figure is 0 or 1 or 2 or 3 or 4 then round to LOW ROUND to 7.8 3 2 Rounding … By Example 600 610 620 630 640 650 660 670 680 690 0 1 2 3 4 5 6 7 8 9 Round 6 7 2 672 To Nearest Hundred Is between and Low Nearest Hundred Click Round Fig √ ² C x ÷ 5 6 7 8 9 + - On 0 1 2 3 4 . = Ans (-) Show Scale Start High 0 700 ROUND (a) To Nearest Hundred 990 (b) 762 (c) 194 (d) 927 (e) 885 (f) 981 (g) 436 Next Show Ans √ ² C x ÷ 5 6 7 8 9 + - On 0 1 2 3 4 . = Ans (-) Nearest Hundred C 0 0 (-) Ans On C √ ² 7 8 9 x √ ² C x ÷ 5 6 7 8 9 + - On 0 1 2 3 4 . = Ans (-) Test 0 4 5 6 ÷ 1 2 3 0 . - = +