There are about 60 million people living in the uk. in every 1000 people there are about 200 who are aged under 16. of the people under 16, about 20% had their sight tested last year. about how many people under 16 had their sight tested last year across the uk?

The first thing we must do for this case is find the percentage of people who have less than 16.
 We have then:
 
 We are now looking for the number of people who have less than 16 in the UK.
 We have then:
 
 Then, the number of people under the age of 16 who had the vision tests are:
 
 
 2,400,000 people under 16 had their sight tested last year across the UK