Answer:
200
Explanation:
First, we know that 1 meter=100 centimeters, so we need to find a common measurement. Lets right it all as meters, so we dont get confused. Then we can find the total area of the floor by multiplying the too side lengths together:
400 centimeters x 200 centimeters= 80000 centimeters!
The total area of the floor is 80,000 centimeters
Now find the area of each tile:
20 centimeters x 20 centimeters= 400 centimeters
Now to find how many of those tiles can fit in that floor, we divide 80,000 by 400.
80,000/400=200
He needs 200 tiles.
Hope this helps!