Video Transcript
There were nine balls in a box. Then, five of them were
removed. How many balls are left?
This is a word problem. Let’s look carefully at the
information we’re given. To start with, we’re told that
there are nine balls in a box. Then, five of them were
removed. If the balls were removed, that
means they were taken away. We have to work out how many balls
are left.
Have you worked out what kind of
problem this is? When we have a number of balls and
we take some away, we need to subtract. So, there were nine balls in a
box. And five were removed or taken
away. To find out how many balls are
left, we need to take away five from nine. Let’s use a number line to help us
subtract.
We need to start at number nine
because there were nine balls in the box at the start. We have to take away five. That means we need to count
backward five starting at number nine. One, two, three, four, five. Nine, eight, seven, six, five,
four. Nine take away five equals
four. To help us subtract, we started at
number nine on the number line and we counted back five. If there are nine balls in a box
and five of them are removed, there will be four balls left. Nine subtract five equals four.
