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Take Three Numbers

Age 7 to 11
Challenge Level Yellow star
Primary curriculum
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We had just a few submissions for this task but they all showed good understanding.


Maisie from  St Mary's C of E (Aided) Primary School sent in the following;

Two odds add one even always equal an even number but two evens add an odd will always equal an odd. Three evens will always equal an odd whereas three odds will always equal an odd too. I was wondering about this last sentence - what do you think?

Evelyn from Harrison Primary School sent in this good illustration of the whole idea;


Susan from The Sacred Heart Primary School in Coventry wrote;

I know that even though I use 2 odd numbers and 1 even [3,7, 2 and 1,9,4] for both calculations they actually come up with different answers[12,14]. THE END!

Zuzanna from St Gregory's Catholic Primary School

Odd number add odd number add even number ALWAYS equals even number. For
example:
3 (odd) + 5 (odd) + 2 (even) = 10 (even).
7 + 9 + 10 = 26
1+3+2= 6 

Thank you all for these contributions.

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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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