 # . Dividing by a Whole Number

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. Dividing by a Whole Number
To divide by a whole number (i.e., the divisor is a whole number) Step 1. Rewrite the problem in long division form. Step 2. Place the decimal point in the quotient directly above the decimal point in the dividend and Divide. Step 3. If necessary, write additional zeros to the right of the last digit following the decimal point in the dividend to allow the division to continue. Example 1. Divide: 29.4  12 Step 1. Rewrite Step 2. Write the decimal point straight up. Then divide. 0 2 . 4 5 -2 4 5 4 Answer: 0.245 -4 8 6 -6 0 Your Turn Problem #1 Divide:  16 Answer: 5.225

Dividing by a Decimal To divide by a decimal (i.e., the divisor is not a whole number) Step 1. Rewrite the problem in long division form. Step 2. Move the decimal to the right (counting the places) to make the divisor a whole number. Then move the decimal point in the dividend the same number of places. Step 3. Rewrite the problem and divide. Example 2. Divide:  0.08 Step 1. Rewrite Step 2. Write the decimal point straight up. Then divide. . 2 places 6 . 3 4 -4 8 2 7 Answer: 6.34 -2 4 3 2 -3 2 Your Turn Problem #2 Divide:  0.09 Answer: 5.75

Rounding the quotient to a specified place value.
The quotient (or answer) was a specific number. In other words, the division ended. We may need to a couple zeros, but it ended. However some division problems may not end as nice, it may have 30 places after the decimal or even go on forever. So, we will sometimes round off to a specified place value. When rounding, we look at the number to the right. 5 or more, round up. 4 or less, round down. This means: When rounding a quotient to a specified place value, we need one more place value in the quotient to round. Examples: If rounding to the tenths place, you must go to the hundredths. If rounding to the hundredths place, you must go to the thousandths. etc Example 3. Divide: 7.2  7 (round to the hundredths place) We need to round to the hundredths place, so we will go to the thousandths place (3 places past the decimal point) Answer: 1.03 Your Turn Problem #3 Divide: 25  11 (thousandths) Answer: 2.273

Procedure for Dividing By Powers of 10, (i.e. 10, 100, 1000 etc.)
Move the decimal point to the left the same number of places as there are zeros in the power of 10. Example 4. Multiply the following: a)  b)  102 a) Since there are 3 zeros, move the decimal point to the left 3 places. Answer: b) 102 = 10  10 = 100. So there are 2 zeros (same as exponent). Move the decimal point to the left 2 places. Answer: 7.295 Your Turn Problem #4 Divide the following: a)  b)  103 Answer: a) b) 7.212 The End B.R. 6-4-08