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21. 99. Rounding. Up or down?. 12. 57. Chris Clements. <date>. Learning Objective:. <Steps to success>. Rounding . Rounding is used to approximate or estimate. Rounding is used to approximate or estimate. Rounding is used to approximate or estimate.
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21 99 Rounding Up or down? 12 57 Chris Clements
<date> Learning Objective: <Steps to success>
Rounding Rounding is used to approximate or estimate. Rounding is used to approximate or estimate. Rounding is used to approximate or estimate. Numbers can be rounded either up or down Numbers are usually rounded up or down to the nearest 10, 100, 1000, 10 000, 100 000 or even a 1, 000 000!
Lets see how well you are doing. Step 1 in the steps to success • Identify the units digit. 1 2 2 5 7 7 3 9 9 7 4 4 9 5 5 2 3 3 continued
Take a look at these number lines. 20 10 11 12 13 14 19 15 16 17 18 If a number ends in a 5, 6, 7, 8 or 9 round up So 15, 16, 17, 18 and 19 round up 26 27 28 29 30 20 21 21 21 21 22 22 22 22 23 23 23 24 24 25 If a number ends in a 1, 2, 3 and 4 round down So 21, 22, 23 and 24 round down continued
Now for the next 2 steps to success. Do you think you know them? 2) Numbers that end with a 5, 6, 7, 8 or 9 round up 3) Numbers that end with a 1, 2, 3 or 4 round down 1 2 3 4 5 6 7 8 9 round up round down continued
Can you see if these numbers need to be rounded up or down. 20 2 3 3 30 Is it closer to 20 or 30? Does it end in a 1, 2, 3 or 4? ROUND DOWN! 30 3 5 5 40 Does it end in a 5, 6, 7, 8 or 9? Is it closer to 30 or 40? ROUND UP! continued
5 3 3 round down 7 4 4 round down 6 8 8 round up 5 9 5 round up continued
3 7 8 9 6 1 9 2 Do these numbers; Round up Round down continued
Rounding up or down Steps to success • When rounding up or down there are three main things to remember; • Identify the units digit. • If the units digit is a 1, 2, 3 or 4 we round down. • If the units digit is a 5, 6, 7, 8, or 9 we round up. continued
Activity <type here>
Plenary Plenary Round up! 28 children go camping. They have a huge tents which 10 children can sleep in. Will they need to round up or down to work out how many tents are needed? 28 children go camping. They have huge tents which 10 children can sleep in. Will they need to round up or down to work out how many tents are needed? 3 3 children will have nowhere to sleep How many tents will they need? How many tents will they need? How many tents will they need? How many tents will they need? If 23 children went, why would it be a bad idea to round down? If 23 children went, why would it be a bad idea to round down? If 23 children went, why would it be a bad idea to round down? If 23 children went, why would it be a bad idea to round down? Round up! Will 238 round up or down? Will 238 round up or down? Why is this more difficult to do? Why is this more difficult to do? Why is this more difficult to do?