12. Dividing Decimals by Decimals January 06, 2016
Warm Up 01‐06‐16
Day 75th of school
1) 12.57 ÷ 4
2) 0.91 ÷ 7
3) 8.96 ÷ 4
4) 6.67 ÷ 3
5) 9 ÷ 12
Dividing Decimals
https://www.khanacademy.org/math/arithmetic/decimals/dividing_decimals/v/dividing‐decimals
Divide decimals
To divide a decimal by a whole number:Use long division.Bring the decimal point up in the answer
56.08
28 04
2
Yesterday we discussed... To divide a number by a decimal:
• Change the divisor to a whole number by multiplying by a power of 10
• Multiply the dividend by the same power of 10
• Divide
• Bring the decimal point up into the quotient
• divisor ) dividend
12. Dividing Decimals by Decimals January 06, 2016
15.6 6.24
Multiply the divisor 15.6 by 10, so that 15.6 becomes 156, and the dividend 6.24 must also be multiplied by 10 to become 624.
156 62.4
0.234 23.4
Multiply by 1000, so that the divisor 0.234 becomes 234, and the dividend 23.4 must also be multiplied by 1000 to become 23,400
234 23400
Try rewriting these problems so you are ready to divide!
Rewrite each problem after multiplying the divisor and dividend by a power of 10.
A)
B)
C)
D)
4.15 ÷ 250
0.08
0.9
68.342 ÷
4.2
678.921
2.2
9 6789.21
22 683.42
8 420
250 4.15
Now do the division for the first two!
40 20 16 40 40 0
250 1650 1500 1500 1500 0
Examples
A. B.
1 Divide
0.78 ÷ 0.02
12. Dividing Decimals by Decimals January 06, 2016
2
0.6 4.866
3
10 divided by 0.25
412.03 ÷ 0.04
5
0.012 24.6
12. Dividing Decimals by Decimals January 06, 2016
There are three types of decimals ‐ terminating, repeating, and non‐terminating, non‐repeating .
A terminating decimal is a decimal that ends.All of the examples we have completed so far are terminating.
A repeating decimal is a decimal that continues forever with one or more digits repeating in a pattern.
A non‐terminating, non‐repeating decimal neither repeats nor terminates. What "famous" decimal number do you know of that is this type?
To denote a repeating decimal, a line, called a vinculum, is drawn above the numbers that repeat, such as 15.32. However, calculators round the last digit and does not show repeating digits.
Let's consider the following...
l÷4Teacher
Notes
12. Dividing Decimals by Decimals January 06, 2016
2÷9 3÷11
31.0645
66232214213210088
120 110100 repeats
Answer to 0.001 place.
51.6
12. Dividing Decimals by Decimals January 06, 2016
266.6
Answer to 0.001 place.
46.6
Answer to 0.001 place.
0.0077
Answer to 0.0001 place.
19.133
Answer to 0.001 place.