4.1 Number Talk: Division Find each quotient mentally.

645 divided by 100

645 divided by 50

48.6 divided by 30

48.6 divided by x

645/100 = 129/20 or 6.45

645/50 = 129/10 or 12.9

48.6/30 = 1.62

48 divided by x = 48.6/x

Step-by-step explanation:

645/100

Factor the number:

= 5*129/100

Factor the number:

= 5*129/5*20

Cancel the common factor:

= 129/20

645/50

Factor the number:

5*129/50

Factor the number:

5*129 / 5*10

Cancel the common factor:

= 129/10

48.6/30

Write the problem in long division format

Multiply the quotient digit (1) by the divisor (30)

Subtract 30 from 48

Add a decimal and bring down the next number

Divide 186 by 30 to get 6

Continue...A few steps later...

Subtract 60 from 60

Solution is 1.62

48.6/x

Re-write division as a fraction:

48.6/x

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