Video Transcript
Ethan and Anthony are competing in
a video game. Ethan scores 3,700 points. Anthony scores 300 points less than
Ethan. How many points does Anthony
score? How many points do they score
altogether?
This problem describes Ethan and
Anthony, who are playing a video game. The first piece of information
we’re given is Ethan’s score. We’re told that he has 3,700
points. And then we’re told Anthony’s
score, or rather we’re told something about Anthony’s score. We’re told that Anthony scores 300
points less than Ethan.
Now, we’re given a bar model, and
this helps us to see the relationship between these two boys’ scores. The bar that represents Ethan’s
score is labeled 3,700. And although the bar representing
Anthony’s score isn’t filled in yet — we don’t know it — we can see that it’s 300
less than Ethan’s. And we’ve got two questions to
answer. And the first one asks us, how many
points does Antony score?
Now, as we’ve said already, his
score is 300 less than 3,700. We’re going to need to subtract to
find the answer. But it’s the sort of calculation we
could do quickly in our heads. We know that 700 take away 300
would leave us with 400. So 3,700 take away 300 is going to
leave us with 3,400.
In the final part of our problem,
we’re asked, “How many points do they score altogether?” What’s their overall total? Now, if we’d have been asked this
right at the start, we might have said to ourselves, well, we can’t find the overall
score. Because to do that, we’d need to
know what Anthony’s score was, and we don’t know that. In other words, we’d have
recognized this as being a two-step problem. First, we’d have needed to find out
Anthony’s score, and then we’d be able to add the two together. But because we’ve already
calculated Anthony’s score, we’ve done the first part of this two-step problem. We just now need to add the two
boys’ scores together.
If we were to sketch another bar
model just to show what we need to do here, it might look like this. We need to add together 3,700 and
3,400. Both our numbers have a three in
the thousands place. And so the total of our thousands
is 6,000. Then we just need to add the
hundreds. Now, we know that 700 plus 300
would be the same as 1,000. So 700 plus 400 will be 100 more
than this. It’s going to equal 1,100. And if we add together our 6,000
with this 1,100, we can see that the boys’ total score is 7,100.
We’ve solved the two parts of this
problem by using bar models to help us. They showed us we needed to
subtract to find the first part and then add for the second. The number of points that Anthony
scores is 3,400 points, and the number of points they score altogether is 7,100
points.
