What is A decreased by 20% and then increased by 20% of that? Please show your work.
1 answer:
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I drew a picture!!
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Maybe you didn't.
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I like to picture things though.
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Ok, a rectangle cut in half.
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Ok, by definition of "half," just multiply the number of rectangles by 2.
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1 x 2 = 2 after cutting the brownies in half.
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2 x 2 = 4 after cutting it in half again.
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4 rectangles now!!
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Doing it the other way... pretend you are starting over from scratch.
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A new batch of brownies!
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But still pay attention to what you already cut.
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Cut down the middle the other direction.
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What's 4 x 2?
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8.
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Now, finally, we multiply the half of the half brownies.
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What's 8 x 2?
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16.
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16 slices.
.
Maybe you didn't.
.
I like to picture things though.
.
Ok, a rectangle cut in half.
.
Ok, by definition of "half," just multiply the number of rectangles by 2.
.
1 x 2 = 2 after cutting the brownies in half.
.
2 x 2 = 4 after cutting it in half again.
.
4 rectangles now!!
.
Doing it the other way... pretend you are starting over from scratch.
.
A new batch of brownies!
.
But still pay attention to what you already cut.
.
Cut down the middle the other direction.
.
What's 4 x 2?
.
8.
.
Now, finally, we multiply the half of the half brownies.
.
What's 8 x 2?
.
16.
.
16 slices.