Some numbers are happy and others are not!
To find out whether a number is happy, square each of its digits, add the answers and repeat. If you end up with 1 the number is happy!
How many happy numbers can you find?
E.g. Consider 19
1^{2} + 9^{2} = 82
8^{2} + 2^{2} = 68
6^{2} + 8^{2} = 100
1^{2} + 0^{2} + 0^{2} = 1
This shows that 19 is a happy number.
Topics: Starter  Arithmetic  Investigations
Was reminded of this Happy Numbers investigation today @KingsmeadOnline. I remember it from a NC Maths level 5 by Vickers & Tippler textbook. The teacher I mentioned this to, couldn't remember it #feelingold. Found a link to @Transum https://t.co/3mTR1gtbip
— Inspiring Maths (@inspiringmaths) June 7, 2019
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Teacher, do your students have
access to computers? 

Here a concise URL for a version of this page without the comments.
Transum.org/go/?Start=January25
Here is the URL which will take them to an interactive Happy Numbers activity.