What is the distance a truck can travel if it moves 7 m/s for 20 seconds?

If it moves 7 m/s and never slows down or speeds up, and it keeps doing this for 20 seconds, then it will cover 7 meters in the 1st second, 7 meters in the 2nd second, 7 meters in the 3rd second, 7 meters in the 4th second, 7 meters in the 5th second, and so on and so forth, twenty times.  All together, it'll cover

7+7+7+7+7+7+7+7+7+7+7+7+7+7+7+7+7+7+7+7 meters

What I did there was:  I wrote down ' 7 ' twenty times.

Now, there's a much easier way to write it.  

In arithmetic, a little dot like this --> · <-- means "times", so we can write

20 · 7  and then we can work it out with our calculator or our pencil.

20 · 7  = 140 meters .

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