1 Uncle Liu wants to build a rectangular grain drying field with a length of 50 meters and a width of 30 meters. Pave 8 cm thick concrete first, then 5 cm thick sand, and finally 1 cm thick cement. How many cubic meters of concrete, sand and cement do you need?

8cm = 0.08m 5cm = 0.05m 1cm = 0.0 1m

Concrete: 50×30×0.08= 120 (m3)

Sand: 50×30×0.05=75 (m3)

Cement slurry: 50×30×0.0 1= 15 (m3)

Put five goldfish in a rectangular container with a bottom length of 20cm and a width of 12cm, and the water level rises 1cm. What is the average volume of each of these little goldfish?

20× 12× 1 ÷ 5 = 48 (cubic centimeter)