## Multiplying and Dividing by 10 and 100 with Dinosaurs

Over the lockdown my son has gone back to his dinosaur fascination (well I say gone back but it has always been there in the background as one of those topics that he finds interesting). This time it is a lot more fact based. And one of things I have noticed he is very interested in is the different measurements. He is becoming a lot more accurate with what he wants to know.

So when we started looking at decimals and dividing by 10 and 100 to get decimals I immediately thought we could do some dinosaur maths.

He had to start by finding the different dinosaur measurements for a selection of dinosaurs. He started with the dinosaurs included in the dinosaur image file from Activity Village (we had printed out these images for another activity so he knew about them and asked to use them for this). For each image he found the weight and length.

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Then he had to multiply each measurement by 10 and 100 and also divide it by 10 and 100. Now I know lots of people just think of this as moving the decimal point (which I totally understand) but I want the kids to understand what we are doing. So we have explained it using place value. If you multiply by 10 you move one column to the left and multiply by 100 (which is 10×10) you move 2 columns to the left. Then dividing by 10 is moving one column to the right and dividing by 100 is moving two columns to the left. I find if the kids get this they can apply it to all kinds of numbers and they can use the same logic with multiplying or dividing by much larger numbers. And the bonus.  Because we used a subject he is interested in not only did he do the 10 dinosaurs I asked for but he has continued creating his own versions of these.

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