# Rules and exercises to estimate numbers to tens, hundreds, or thousands.

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Rules and exercises to estimate numbers to tens, hundreds, or thousands

Rounding to Tens When estimating to tens look at the ones digit. If the digit is 5 or more, the rounding goes up. If the ones digit is 4 or less, the rounding goes down. 10, 11, 12, 13, and 14, all become 10 15,16, 17, 18, and 20, all become 20

Now, try to estimate to tens on your own 23121 34234 45365 56829 67283 88507 91756

These are the right answers. How many did you get right? 2320121120 3430234230 4550365370 5660829830 6770283280 8890507510 9190756760

ESTIMATING TO HUNDREDS When estimating to hundreds, the tens digit determine if the estimate goes up or down. Like in the rounding to ten, if the tens digit is 5 or more, the estimate goes up. If the tens digit is 4 or less, the estimate goes down. 123, 135, 109, 149, all go down to 100 150, 161, 172, 183, 199, all go up to 200

Now, you try to round to hundreds 102 134 145 187 298 980 875 808 1,4532,354 2,6543,765 7,3458,543 9,2309,999

How many did you get right? 102100 134 100 145100 187 200 298300 9801,000 875900 808 800 1,4531,5002,354 2,300 2,6542,7003,765 3,800 7,3457,3008,543 8,500 9,2309,2009,999 10,000

Estimating Thousands When estimating to thousands, the hundreds digit is the one that determines if the number goes up or down. If the hundreds digit is 5 or more the estimation goes up. If the hundreds digit is 4 or less, the estimation goes down. 1,209, 1389, 1451, and 1499 all become 1,000 2,500, 2,676, 2,765, and 2999 all become 2,000

Now, try to estimate to thousands 1,59832,456 3,46347,678 4,87569,087 5,70978,234 7,08912,909 4,32387,109 6,67590,534

How well did you do? 1,5982,00032,45632,000 3,4633,00047,67848,000 4,8755,00069,08769,000 5,7096,00078,23478,000 7,0897,00012,90913,000 4,3234,00087,10987,000 6,6757,00090,53491,000

Estimate these numbers to tens, hundreds, and thousands 7, 461 8,071 9,087 4,690

Did you get them right? 7, 461 7,4607, 5007,000 8,071 8,0708,1008,000 9,087 9,0909,1009,000 4,690 4,6904,7005,000

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