Video Transcript
What is 14 subtract eight. Hint: Subtract from 10.
It looks like we need to take away
a ones number from a teen number in this question. We need to subtract eight from
14. But wait a second. The hint that we’re given doesn’t
say subtract from 14; it says subtract from 10. Why did it say this? It’s a bit strange. In the picture, we can see 14
counters that are being put into 10 frames. And this gives us a little bit of a
clue as to what we need to do. Because by using 10 frames, we can
see that the number 14 is the same as one lot of 10 and then four ones. So instead of taking away eight
from 14, by splitting the number up like this, we can take away eight from 10.
And this is what the hint is really
telling us. It’s really saying to us, don’t
take away from the whole amount. Now that you’ve split up 14 into
one 10 and four ones, just look at the one 10. It’s much easier to subtract from
10. And the reason it’s much easier and
quicker to subtract from 10 is because all we need to do is to think of the pairs of
numbers that go together to make 10. And because we want to subtract
eight, all we have to do is think of the number that goes together with eight to
make 10. Now, if we draw a line here on our
10 frame, we can see that eight and another two go together to make 10. So if we start with 10 and take
away eight, we’ll be left with two.
Now remember, the calculation we’re
trying to work out here is 14 take away eight. So to see how many counters we’ve
got left, we need to add the two parts we’ve got back together again. And two plus four equals six. To find the answer to 14 take away
eight, we first split up the number 14 into 10 and four. We did this because subtracting
from 10 is much quicker than subtracting from 14 because we know all the pairs that
go together to make 10. 10 take away eight leaves us with
two. Then we had to put the two parts
back together again. Two plus the four ones equals six
altogether. And that’s how we know that 14
subtract eight equals six.
