Question

a rectangle garden is paved with 1m square paving stones. the garden is 15m long and 10m wide how many paving stones are used?

Answer 1

First you need to find the area of the garden. 
a=lw
a=(15)(10)
a=150 meters

150/1=150

you need 150 paving stones.

Answer 2

So first you need to know how much area the garden is

so areia=legnth times width

area=15 times 10
area =150 m^2 (square meters)

each stone is 1 by 1 so area of each stone is 1 m^2

150/1=150
you need 150 paving stones