Maths geeks - explain how to find halfway point (decimal numbers)

[BlueSkySunnyDay]

My son does not appear to have a clue and I haven't needed to do it since school!!

Could you explain the technique - e.g. half way between 4.6 and 4.94

or 4.9 and 5.12

Add them both together and divide by 2. Hope that helps!

I was kind of thinking along them lines but I didn't want to guide him wrongly!

Subtact the smaller number from the larger then divide the difference by 2.

But make sure he can do it with two digit numbers first. I teach v able y5 top set and none of them could reliably do eg 46 and 92 at start of year. Can do decimals now and the method we use is find the diff then halve it.

"Subtract the smaller number from the larger then divide the difference by 2."

But then you'd have to add the result to the smaller number ... Surely would be quicker and easier to

Add them both together and divide by 2

It is easier but the kids in my class didn't "get it". They didn't understand why that worked (most are at a level 5c or 5b so able). I demonstrated the find the difference using a number line and showing the midpoint. They still sketch out numberlines now to help if stuck

Thanks sometimes you can google about and not find a "how to", I found plenty offering tuition though.

He got it really quickly and shot through the sheet in the end.

He did them on paper and I checked them using a calculator