# Question Video: Solving Multiplicative Comparison Problems Using Models and Multiplication by 5 Mathematics • 4th Grade

The snake is 5 times as long as the caterpillar. Pick the model that shows how long the snake is.

02:50

### Video Transcript

The snake is five times as long as the caterpillar. Pick the model that shows how long the snake is.

In this question, we’re being asked to compare two things, the length of the snake and the length of the caterpillar. And we’re going to need to use multiplication to solve this problem. We know this because the question tells us the snake is five times as long as the caterpillar. When we compare two things using multiplication, we call this a multiplicative comparison problem. We have to use multiplication to calculate how long the snake is.

When we’re trying to solve multiplicative comparison problems like this, it helps to sketch a bar model. We’re not told how long the caterpillar is. We could use this bar to represent the caterpillar. And we know the snake is five times longer than this. So, the bar representing the length of the snake would look like this: five times the length is the bar representing the caterpillar.

Now, we have to pick the model which shows how long the snake is. Let’s look closely at the first model. Did you notice that this cube train has been made using groups of three cubes? How many groups of three are there? One, two, three, four, five, five groups of three or three multiplied by five. So, if the caterpillar is three cubes long, then each of the bars would be worth three cubes. And the length of the snake would be five lots of three. So, this is the model that shows how long the snake is.

If the length of the caterpillar is one times three, the length of the snake must be five times three. This model shows three plus five, not three times five. And this model shows two plus three, which equals five. We picked the model which is five times as long as the caterpillar.