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Rounding by finding the halfway number

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This video will explain how to round by finding the halfway number. Step 1: Draw a number line Step 2: Determine which tens (or hundreds) the starting number is in between, then write them on either side of the number line Step 3: Determine the number that is halfway between the two tens (or hundreds), then write that number in the middle of the number line Step 4: Compare the starting number to the halfway number. If the starting number is less, then round down. If the starting number is equal to or greater than the halfway number, then round up.

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alright another difference between the math instruction the most of us received his kids and the strategies that are being emphasized with with our current students is the way that since round numbers again a number line is used I cannot emphasize enough how valuable the concept of a number line is so what students are trained to do is think of their number on a number line  32  since a rounding to the nearest ten we're going to the nearest 10 going down in the nearest ten going up there to count down from 30 to 31 30 30 would be the first 10 they could get to going down they were to count up 3233 on and on  it would realize the nearest 10 going office 40 so those are there two choices to round what they then do is find the halfway number between these two numbers and see which side of the halfway number the number they're starting with is on  so students are trains  so thank her trained to realize that the scream 30 + 40 is 10  half of that distance or that difference is 5  which games that the halfway number is 5 more than 30 and 5 less than 40 now course we all know that the halfway number between these would be 30 $0.05 32 is less than the halfway number it would get rounded down  the 3rd we can see the same principle at work with larger numbers rounding 171 to the nearest hundred again student start with a number line they Place their number on the number line they think about the nearest hundred going down and the nearest hundred going up which in this case would be 100  M200 the entire distance between 100-200 is 1 half of 100 is 50 so the halfway number even though my drawing may not make it look like it's halfway but the halfway number would be 50 more than 150 less than 200 which is a course 1 your 50  students are then able to see that the number they're starting with is greater than the halfway number and thus it should be rounded up to the 100 in this case 200  there will be more videos on rounding but that's just a brief introduction for now as always thanks for your time

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Rounding by finding the halfway number

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