WEBVTT
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William wants to tile the floor of a rectangular room measuring one meter by eight meters.
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If the tiles are square with length 20 centimeters, how many will he need?
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Let’s start by drawing a sketch of this rectangular room.
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We know that the shortest side will be one meter.
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And the longer side will be eight meters.
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We’re told that William wants to put down square tiles that are 20 centimeters long.
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If William starts by putting tiles along the one-meter width, then how many 20-centimeter tiles will fit into this edge?
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Let’s recall that one meter is equal to 100 centimeters.
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So we need to work out how many 20-centimeter tiles will fit into 100 centimeters.
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We calculate 100 divided by 20, which is five.
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Now we know that, along the width one meter, there will be five tiles.
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Now let’s consider how many tiles will fit along the length of the rectangular room that we know is eight meters long.
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Here we can consider how many centimeters will be in eight meters.
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If we consider the conversion that one meter is equal to 100 centimeters, then eight meters is eight times larger.
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So our 100 centimeters must also be eight times larger.
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So we can say that, in meters, it’s equal to 800 centimeters.
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And now to calculate how many 20-centimeter tiles fit into 800 centimeters, we work out 800 divided by 20, which gives us 40.
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So now if we look at the diagram of our rectangular room, we can see that there are 40 tiles along the length and five tiles along the width.
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We could think of this as five rows of 40 tiles each.
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To work out the total number of tiles, this would be equal to five times 40, which is 200.
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So our answer for the number of tiles that William needs is 200.