# Video: Solving Word Problems by Multiplying One-Digit Numbers by Two-Digit Numbers

A car moves at a speed of 72 miles per hour. How far will it travel in 3 hours?

01:58

### Video Transcript

A car moves at a speed of 72 miles per hour. How far will it travel in three hours?

To solve this problem, we’re gonna use the speed–distance–time triangle. And we’re gonna use this triangle to help us find which equation we’re gonna use to find out distance. From the triangle, we can see that the distance is equal to the speed multiplied by the time. And you can also use this triangle to find the other equations. So we could see that the speed would be equal to our distance divided by time. And our time would be equal to our distance over our speed.

Okay, great! So we now have the equations. But the one we’re gonna use this time is distance equals speed multiplied by time. So we see what we’ve got given in our question. Well, we know that the speed is 72 miles per hour. And our time is three hours. Our distance is what we want to know.

Okay and we can now find this by substituting our values into our equation, which gives us that our distance is equal to three multiplied by 72. And we can solve this by using a written method because this may be on a non-calculator paper. So I’ve written in the column method here.

So first of all, we do the three multiplied by the two, which gives us six. And then we’d be doing the three multiplied by the seven, which is 70, cause it’s seven 10s. And three multiplied by 70 is 210. So therefore, we can see that our answer is 216. I’m not forgetting our units, which is miles. So we now know that our car travelling at a speed of 72 miles per hour will travel 216 miles in three hours.