Using Bar Models To Solve Multi Step Multiplication Problems

Hi, I'm Ben and in this video we're going to look at how to solve a multi step multiplication word problem using the bar model. This is our question. Ischool's paper chain is seven times longer than Terry's paper chain. It takes 210 paperclips to measure eachell's paper chain. How many fewer paperclips would it take to measure Terry's paper chain? Okay, again, the bar model works really, really well here. So does a good understanding of multiplication and division. Let's have a look. So there's Terry's paper chain. We're going to consider that as one part. And eSchools paper chain is seven times larger. So that'll be seven part. Again, it's really important to make sure that each part is fairly proportional. So that helps with the understanding. Now we know that Eschool's paper chain is 210 paper clips long. From here the children can see that if the part is the whole is made of seven parts, we can do 210 divided by seven, Which equals 30. They could look at it as 21 divided by 7. And they can use their place value understanding to help with that. So we then label each one. So if each part is worth 30 on Eshal's paper chain, then Terry's part must also be 30. Now we have to come back to the question again. This is the final stage and this is really, really important. How many fewer paper clips would it take to measure Terry's paper chain? So if Terry's is 30 initials is 210, we need to look at 210 minus 30, which will be 180. And that's how we use the bar model to solve multi step multiplication problems.