Caught in the Web
Can you estimate the mass of insects caught by spiders in the UK each year?
Age
14 to 16
Challenge level
The mass of insects caught by spiders in a year in the UK is approximately equal to the mass of the human population of the UK.
Assuming this population is 60 million and the average mass of a human is 70 kg, what is the mass, in tonnes, of insects caught by spiders per year in the UK?
If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.
There are 1000 kg in 1 tonne.
Answer: 4 200 000 tonnes
60 million x 70 kg = 4 200 million kg
1 tonne = 1000 kg
4 200 million kg = 4 200 000 000 kg
= 4 200 000 tonnes