# Grades 4 to 9 Magic Numbers

*By toni On 5 November, 2017 · Leave a Comment*

What patterns do you see in them?

Suppose you have to share 9872 gold coins between 8 people.

You give the coins out in thousands until there are less than 8000 left.

Then you give out one hundred at a time until there are less than 800, then 10 at a time then 1 at a time.

You could do this sharing by splitting the coins into 4 piles and sharing each of the piles between the 8 people.

You give each person 1000 + 200 + 30 + 4 coins.

Use the coin sharing story to explain the division sum:

9872 ÷ 8 = 1000 + 200 + 30 + 4 = 1234

The brackets in these calculations tell you that you must do the calculation inside the brackets **first**.

Using the subtraction calculations that you have already done can you complete all of these calculations without using a calculator?

What patterns do you notice? Why do you think that the ancient Egyptians called these numbers *magic numbers*?

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