How many tiles do you need to use if you want to use a 6-decimeter-long square tile for your room? How many tiles do you need if you want to use a 12 decimeter square tile instead

How many tiles do you need to use if you want to use a 6-decimeter-long square tile for your room? How many tiles do you need if you want to use a 12 decimeter square tile instead

The area of each block is 6 × 6 = 36 square decimeters
Room area 36 × 150 = 5400 square decimeters
How much do you need 5400 △ 12 = 450