Video Transcript
Emma is trying to solve this word
problem. There were 41 birds in a tree. 15 of them flew away. How many birds are in the tree
now? Emma said the answer was 41 plus 15
equals 56. What did she do wrong? What is the correct answer?
We can use a bar model to help us
picture the problem. We know that there were 41 birds in
the tree and that 15 of them flew away. We need to work out how many birds
are left.
To work out how many are left, we
start with 41 and we subtract 15. One way to do this is to partition
15 into a 10 and a five. First, we can take away 10 from 41
to give us 31. Then, we can take away five from
31. Counting backwards, we have 30, 29,
28, 27, and finally 26. So, 41 take away 15 is 26.
Going back to the question, we are
asked what Emma did wrong and what is the correct answer? We can see that Emma added when she
should have subtracted, as she said the answer was 41 plus 15 equals 56. And the correct answer is 41 take
away 15 equals 26.
In this question, we have used a
bar model to help picture the problem. There were 41 birds, 15 flew away,
and there are now 26 left in the tree.
