Video Transcript
Complete: What centimeters equals
four meters and 70 centimeters.
To help us answer this question,
we’re shown a part–whole model. Now, normally, if we wanted to find
the missing number here, that’s the missing whole, with a part–whole model, we just
add the two parts together. But in this particular question, we
can’t just add four and 70 to find the answer. Can you see why? In this question, the numbers four
and 70 represent two measurements: four meters and 70 centimeters. We can’t just add four and 70
together because they’re different units. If we look at the missing number in
our part–whole model, we can see that we’re looking for a number of centimeters. And we can see this in the
question, too.
For us to write this whole
measurement in centimeters, we’re going to need to change those four meters into
centimeters, aren’t we? Is there a fact We know that can
help us? We know that one meter is the same
as 100 centimeters, and so four meters is the same as four lots of 100 centimeters
or 400 centimeters. Should we write this on our
part–whole model to help us? Instead of four meters, let’s write
400 centimeters instead. They’re exactly the same. Now we can add our two parts
together. 400 plus another 70 equals 470. And so we know that four meters and
70 centimeters is exactly the same distance as 470 centimeters. Our missing number is 470.
