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What's My Weight?

There are four equal weights on one side of the scale and an apple on the other side. What can you say that is true about the apple and the weights from the picture?

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

Age 7 to 11
Challenge Level

Lights in Copenhagen
Look carefully at the image above.
Make an estimate of how many light fittings you can see.
Now count them.
What do you estimate the total number of lights on the fitting to be?
How can you decide if your estimate is a good one?
Did others make better (or worse) estimates? How can you decide?

What else do you notice about the light fittings?

Now, look carefully at the rods that the light fittings are attached to:
  • What do you notice?
  • How many rods are there?
  • How many different shapes can you see?
  • Is the resulting figure regular?


The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.
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