Step by step
The question
Question: A car drives at 64 km/h.
How many hours does it take to drive 208 km?
1 Find what we know
What do we know?
The car goes 64 km in each hour.
The trip is 208 km.
What do we want?
How many hours.
2 Name the unknown
We don't know how many hours.
So we call it x.
How far we go: speed times time.
64 km/h means 64 km in each hour.
Let's draw it.
The car starts here.
It goes 64 km in each hour, for x hours.
The whole trip: 208 km.
3 Write the equation
In words: speed times time makes the distance.
So the equation is 64x = 208.
Now we solve it.
Is x alone now?
Not yet: 64x means 64 times x.
How do we remove it?
4 Remove the 64
To remove times 64, we divide by 64.
We do it on both sides, so they stay equal.
64 divided by 64 is 1.
They cancel each other.
So just x is left.
We can make 208/64 simpler.
It is the same as 13/4.
So x = 13/4.
5 Answer the question
13/4 is 3.25.
So it takes 3.25 hours.
6 Check
Let's check in the story.
3.25 hours at 64 km/h: 3.25 times 64 is 208 km, like the story says.
Check it with the picture.
The car drives 3.25 hours at 64 km/h: 208 km, the whole trip.
So the answer is right!
Let's look back.
First: find what we know.
Then: name the unknown.
Then: write the equation.
Then: solve it.
Then: answer the question.
Last: check.