Making 100

Pupils write out the digits 1 to 10 like this:

1   2   3   4   5   6   7   8   9   10

The aim is to create an expression that equals 100 by putting as many + – X and / signs between the digits as they like. You might like to demo one like this:

1    2   3 + 4   5   6  X 7 / 8 – 9 = 123 + 456 X 7 / 8 – 9 = 513

Obviously this one is too high but it does illustrate the method. You can decide whether the pupils must use BODMAS or not (I’d suggest they do!) and whether they are allowed to put brackets in as well.

There are many solutions and you might like to post them in the comments section below when you find them!

Thanks to Cat for this engaging little starter. It might make a brilliant homework too!

Have fun!

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Wanna be in my gang?

A great little game to get kids thinking about types of numbers.

Think of a particular type of numbers that you want the pupils to guess. This could be square numbers, cube numbers, triangle numbers, even numbers etc… Tell the pupils that they need to guess a number between 0 and 100. If their number matches your hidden criteria then you say “you’re in my gang”. If the number doesn’t match your hidden criteria then you say “you’re not in my gang”. The pupils keep guessing until they work out what type of numbers you are thinking of.

Big thanks to Nicola for this great idea.

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