Back to School

Mr. Sunshine tells the children they will have 2 hours of homework. After several calculations, Harry says he hasn't got time to do this homework. Can you see where his reasoning is wrong?

The Magic Number and the Hepta-tree

Find the exact difference between the largest ball and the smallest ball on the Hepta Tree and then use this to work out the MAGIC NUMBER!

Shedding Some Light

Make an estimate of how many light fittings you can see. Was your estimate a good one? How can you decide?

What's My Weight?

Age 7 to 11 ShortChallenge Level

We had a solution to this problem from someone who didn't give their name or school - but thank you!

From the picture of the scales, the apple must weigh less than the four weights altogether.
If the apple weighs $180g$, for the scale to be balanced the weights would have to be $45g$ each because there are four of them. But we know from the picture that the apple weighs less than the weights put together, so each weight must be more than $45g$.
If the apple weighed $375g$, then for the scale to be balanced, each weight would be $93.75g$. So, for the weights to be heavier than the apple, each one must be more than $375g$.
One kilo is $1000g$ and four $250g$ weights would also weigh $1000g$ altogether so the scale would be balanced.