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

First there is the hepta-tree hung with silver balls.

Hepta-Tree. The balls on the hepta-tree say "7% of 614", "13% of 330", "17% of 253", "19% of 226", "23% of 187", "61% of 71" and "77% of 56"

Try estimating the amount on each ball. Do you think the balls will have a similar value?

We have to find the exact difference between the largest ball and the smallest ball and then use this number to find a percentage of 247.

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!