Estimating or Rounding Rules and exercises to estimate

Rounding to Tens �When estimating to tens look at the ones digit. �If the

Now, try to estimate to tens on your own 23 34 45 56 67

These are the right answers. How many did you get right? 23 34 45

ESTIMATING TO HUNDREDS �When estimating to hundreds, the tens digit determine if the estimate

Now, you try to round to hundreds � 102 � 145 � 298 �

How many did you get right? � 102 � 145 � 298 � 875

Estimating Thousands �When estimating to thousands, the hundreds digit is the one that determines

Now, try to estimate to thousands � 1, 598 � 3, 463 � 4,

How well did you do? � 1, 598 � 3, 463 � 4, 875

Estimate these numbers to tens, hundreds, and thousands � 7, 461 � 8, 071

Did you get them right? � 7, 461 � 7, 460 � 8, 071

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Estimating or Rounding 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 23 34 45 56 67 88 91 121 234 365 829 283 507 756

These are the right answers. How many did you get right? 23 34 45 56 67 88 91 20 30 50 60 70 90 90 121 234 365 829 283 507 756 120 230 370 830 280 510 760

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 � 145 � 298 � 875 � 1, 453 � 2, 654 � 7, 345 � 9, 230 134 187 980 808 2, 354 3, 765 8, 543 9, 999

How many did you get right? � 102 � 145 � 298 � 875 � 1, 453 � 2, 654 � 7, 345 � 9, 230 100 300 900 1, 500 2, 700 7, 300 9, 200 134 187 980 808 2, 354 3, 765 8, 543 9, 999 100 200 1, 000 800 2, 300 3, 800 8, 500 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, 598 � 3, 463 � 4, 875 � 5, 709 � 7, 089 � 4, 323 � 6, 675 32, 456 47, 678 69, 087 78, 234 12, 909 87, 109 90, 534

How well did you do? � 1, 598 � 3, 463 � 4, 875 � 5, 709 � 7, 089 � 4, 323 � 6, 675 2, 000 3, 000 5, 000 6, 000 7, 000 4, 000 7, 000 32, 456 47, 678 69, 087 78, 234 12, 909 87, 109 90, 534 32, 000 48, 000 69, 000 78, 000 13, 000 87, 000 91, 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, 460 � 8, 071 � 8, 070 � 9, 087 � 9, 090 � 4, 690 7, 500 7, 000 8, 100 8, 000 9, 100 9, 000 4, 700 5, 000