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'The Magic Number and the Hepta-tree' printed from http://nrich.maths.org/

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The Mathemagician needs to break a dreadful spell! Help him to find the magic number that will do the trick!

Here is the hepta-tree hung with silver balls.

Hepta-Tree. The balls on the hepta-tree say

Do you think the balls will have similar values?

Try estimating the amount on each ball.

In order to break the spell, firstly find the exact difference between the largest ball and the smallest ball.

Multiply your result by $244$.

Round this to a whole number and that gives us the MAGIC NUMBER!

Give this number to the Mathemagician and the terrible spell will be broken for ever!