Multiplying Decimals

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Multiplying Decimals

• A Visual Approach

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Take a piece of paper and cut it in half.
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Take a piece of paper and cut it in half.
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Take a piece of paper and cut it in half.
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Now take what is left and cut it in half.
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Now take what is left and cut it in half.
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You should end up with ¼ of a piece of paper.
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You just did the following multiplication problem
.50 x .50 .25
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Notice that when you multiply two fractions
together, the answer gets smaller instead of
bigger.
.50 x .50 .25
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Notice that when cut the paper in half and then
in half again, your paper got smaller.
.50 x .50 .25
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Using the word of can help you make sense of
multiplication problems that involve fractions.
of means times
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Using the word of can help you make sense of
multiplication problems.
4 x 3 means 4 of 3
4 x 3 12
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Using the word of can help you make sense of
multiplication problems, especially when
fractions are involved.
½ x ½ means ½ of ½
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Using the word of can help you make sense of
multiplication problems, especially when
fractions are involved.
½ x 4 means ½ of 4
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Using the word of can help you make sense of
multiplication problems, especially when
fractions are involved.
½ x 4 means ½ of 4
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Using the word of can help you make sense of
multiplication problems, especially when
fractions are involved.
½ x 4 means ½ of 4
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Using the word of can help you make sense of
multiplication problems, especially when
fractions are involved.
½ x 4 means ½ of 4
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Using the word of can help you make sense of
multiplication problems, especially when
fractions are involved.
½ x 4 means ½ of 4
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Using the word of can help you make sense of
multiplication problems, especially when
fractions are involved.
½ x 4 means ½ of 4
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Using the word of can help you make sense of
multiplication problems, especially when
fractions are involved.
½ x 4 means ½ of 4
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Lets take a look at some more multiplication
problems through the use of pictures.
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Here is our problem
Fractional Form
Decimal Form.4 x .5
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Here is our problem
Fractional Form
Decimal Form.4 x .5
.5 5 10
.4 4 10
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The overlap of the grids is the product.
Fractional Form
Decimal Form.4 x .5
.4 x .5 .20
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Here is our problem
Fractional Form
Decimal Form.6 x .3
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Here is our problem
Fractional Form
Decimal Form.6 x .3
.3
.6
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The overlap of the grids is the product.
Fractional Form
Decimal Form.6 x .3
.6 x .3 .18
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Here is our problem
Fractional Form
Decimal Form.9 x .6
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Here is our problem
Fractional Form
Decimal Form.9 x .6
.6
.9
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The overlap of the grids is the product.
Fractional Form
Decimal Form.9 x .6
.9 x .6 .54
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Practice Time!
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DIRECTIONSWrite the equation that is shown by
each picture. Use both decimals and
fractions.EXAMPLE.2 x .3 .06and
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1
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.6 x .2 .12
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2
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.4 x .3 .12
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3
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3
.8 x .5 .40
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4
40
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.2 x .2 .04
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5
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5
.9 x .1 .09
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6
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.3 x .7 .21
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7
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.1 x .1 .01
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8
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.5 x .3 .15
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You will need to use your 10 by 10 grids for the
next 4 problems. You will also need 2 colored
pencils of different colors.
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Color the grid to represent the following problem
Fractional Form
Decimal Form.4 x .4 .16
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Color the grid to represent the following problem
Fractional Form
Decimal Form.4 x .4 .16
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Color the grid to represent the following problem
Fractional Form
Decimal Form.2 x .7 .14
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Color the grid to represent the following problem
Fractional Form
Decimal Form.2 x .7 .14
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Color the grid to represent the following problem
Fractional Form
Decimal Form.5 x .8 .40
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Color the grid to represent the following problem
Fractional Form
Decimal Form.5 x .8 .40
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Color the grid to represent the following problem
Fractional Form
Decimal Form.8 x .3 .24
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Color the grid to represent the following problem
Fractional Form
Decimal Form.8 x .3 .24
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The End!