640×2×2=2400 meters
Woodpeckers can catch 640 pests every day, which is about 8 times that of frogs. How many pests can frogs catch in a week? 640÷8=80 (only) 80×7=560 (only)
The students took part in the gymnastics performance at the opening ceremony of the sports meeting. 525 students are arranged in three phalanxes, and each phalanx stands in seven columns. How many students are there in each column? 525÷7÷3=25 (pieces)