Video Transcript
Complete the following: one plus
seven equals what.
In this question, we need to find
the total of one and seven. Now we’re shown a picture of a
number line underneath this addition. Perhaps we could use it to count
on, so we could start at the number one and then count on another seven. To do this, we’d need to make a
jump of one, two, three, four, five, six, seven. We’ve arrived at the number eight,
and so we know one plus another seven is eight. But you know, there’s a much
quicker way to find the answer because counting on seven took a while, didn’t
it?
When we add two numbers together,
it doesn’t matter which order we add them. So although we could start at one
and then count on another seven, we could get the same answer by switching the
numbers around. We could start at the number seven,
and then we’d only have to count on another one: seven and then eight. If we’re adding a small number onto
another number, it’s often useful to start with the bigger number and then just
count on the small number. We found the answer by starting at
one and counting on seven, but also by starting at seven and counting on one. One plus seven equals eight.
