Rounding Numbers Year 6 Objective To round a
Rounding Numbers Year 6 Objective: To round a decimal number to the nearest whole number
Things to think about… • When do we use rounding in our everyday lives? • Why do we round numbers?
We often round money, time and measurement. This pizza costs € 6. 10 Rounded to the nearest euro, it costs € 6. This trousers costs € 12. 99 Rounded to the nearest euro, it costs € 13. This mobile costs € 399. 99 Rounded to the nearest euro, it costs € 400.
We often round money, time and measurements. The time shows 12: 09 It’s just gone 12 o’clock. The time shows 11: 56 It is nearly 12 o’clock.
We often round money, time and measurements. A length measuring 149. 9 cm. We can say that it is around 150 cm. This thermometer reading is 82. 1°. We can say that it is around 82°.
Things to think about… • When do we use rounding in our everyday lives? • Why do we round numbers? Rounding makes it easier to describe and understand numbers. You don’t always need to be exact.
What are decimal numbers? Why are they so important?
Place Value Chart
https: //www. youtube. com/watch? v=KG 6 ILNOi. Mg. M Video: Decimal Numbers 0. 47 s – 5. 57 s
What is Tenth?
Understanding place value 1 Ten is 10 times 1 One 10 1
0. 5 1. 3 2. 9 http: //www. laubach-on. ca/sites/default/files/Module%206 -Decimals%20 in%20 Real%20 Life. pdf
Rounding To The Nearest Whole Number 6. 8 Our task is to decide if the number is closer to: 6 6 7 or 6. 5 6. 8 7 6. 8 = 7 (to the nearest whole number) 8 Is 6. 8 above or below 6. 5?
Rounding To The Nearest Whole Number 24. 3 24 24 or 24. 3 25 25 24. 3 = 24 (To the nearest whole number) 26 Is 24. 3 above or below 24. 5?
Find the place value and circle that digit Round 23. 11 to the nearest whole number Circle the number just before the decimal point 23. 11
Move to the right, Underline it Look to the right of the number we have circled Underline the number in the tenths place.
0 through 4 Circle stays the same If the number we underlined is 0, 1, 2, 3, or 4, we leave the number in the circle as it is.
Digits to the right change to ZERO All the digits to the right of the number in the circle, change to ZERO
x 23. 0 23. 50 24. 0 23. 11 is closer to 23 rather than 24
Find the place value and circle that digit Round 23. 72 to the nearest tenths 23. 72
Move to the right, Underline get it Look to the right of the number we have circled 23. 72 Underline the number in the tenths place.
0 through 4 Circle stays the same If the number we underlined is 0, 1, 2, 3, or 4, we leave the number in the circle as it is. 23. 72
5 through 9, Add 1 in this game If the number we underlined is 5, 6, 7, 8, or 9 we add 1 to the number in the circle. 23. 72
Digits to the right change to ZERO All the digits to the right of the number in the circle, change to ZERO 24. 00
x 23. 0 24. 0 23. 50 23. 72 is closer to 24 rather than 23
Round the following to the nearest whole number: (1) 4. 9 5 (6) 287. 3 (2) 7. 9 8 (7) 9. 6 (3) 42. 2 42 (8) 49. 9 50 (9) 99. 5 100 (10) 899. 5 900 (4) 97. 5 (5) 66. 3 98 66 287 1010
Think about… Write as many numbers as you can think of which round up to 30. Hint: You can also include decimal numbers.
- Slides: 28