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Topic 1-4 Estimating Quotients. Ms. Hubbard 5 th Grade Sept. 1, 2011. Estimating Quotients Choice #1 Choice #2. Rounding When you round the dividend, try to round to the nearest tens or hundreds place.
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Topic 1-4 Estimating Quotients Ms. Hubbard 5th Grade Sept. 1, 2011
Estimating QuotientsChoice #1 Choice #2 Rounding • When you round the dividend, try to round to the nearest tens or hundreds place. • Once you choose to round up or down, then solve the division problem with the new rounded number • See example on next page 3 ***Remember you can get multiple answers with both strategies*** Multiply • Choose a number 1-100. • Then multiple the 1-100 number by the divisor. • Remember when you use this method it is a process of elimination. It may take you a few tries to find a number that will get you close enough to the dividend. • See example on page 4
Example: Rounding • 195 ÷ 4 = ? - First, think what number around 195 could be easily divided by 4? Answer: 200 - Second, now that we have our new dividend our problem now looks like this: 200÷4=? - Solve (you should be able to solve this using mental math), if not use our MSBD method to divide. 200 ÷ 4 = 50 - So are answer would be 195 ÷4 = about 50
Example: Multiplication • 195 ÷ 4 =? • Remember that when using this method, your basically doing process of elimination. So you will have to solve multiple multiplication problems. • First, choose a number 1-100 (I always start with 100 and work my way down). Then if 100 is to big cut it in half (50). So 200 is really close to 195. Lets go just a few numbers below 50 this time to see if we can get closer. So our answer would be 195 ÷ 4 = about 49 100 50 49 X 4x 4 x 4 400 (bigger than) 200 (really close) 196 (really, really) (195) (close)