Ratio

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Ratio
My bikes fuel has a ratio of oil to petrol 1
25
Sounds complicated
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Using the simplest ratio to describe different
quantities.
Sue is explaining how to use a ratio to describe
red and green hearts.
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Count the number of red and green hearts 4 RED
and 8 GREEN
Record the numbers using headings like this
Red Green 4 8
The says to
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Try to write the ratio in its simplest terms
Red Green 4 8 2 4 1 2
Divide by 2
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The ratio of red to green is Red Green 1
2 This tells you that there are 2 green hearts
for every red heart
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Copy and complete this chart
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Copy and complete this chart
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Sharing a quantity into a given ratio
For example, share 36 into the ratio 2 7
First ADD the ratio 2 7 9 Second DIVIDE this
answer into the quantity to be shared 36 9
4 Third MULTIPLY the ratio by this answer 2 X 4
7 X 4 This is the answer 8 28
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To share into a given ratio, the things to do are


X
Share 32 into the the ratio 3 5 3 5 8 32
8 4 3 X 4 12 5 X 4 20 Answer 12 20
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Share these into the given ratio
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Share these into the given ratio
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Finding an unknown number that fits a given ratio
Example If the ratio of red beads black beads
is 3 5, how many black beads will I need for 21
red beads? Red Black 3 5 21 ?
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First find the number that you multiply 3 by to
get 21
Red Black 3 5 21 ?
X 7
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Red Black 3 5 21 42
X 7
X 7
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Another Example
Red Black 2 7 12 ?
2 X 6 is 12 so you multiply 7 by 6 to get the ?
X 6
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Red Black 2 7 12 42
X 6
X 6