Raising the money

A few days ago we did a maths problem about camp. We do this in a book called 'At Camp'. What we  needed to do is to find out how much money there is for each activitie. As you can see on the pic below there is a meter. The meter shows how much money they raised. We had to work out how much they raised for each activitie.  We worked this out in our day books. I worked it out with Hannah.

As you can see me and Hannah figured out that the meter is going up in 200s. This will make it easier for us. Then we took away how much they raised before. For exsample: if they raised $1200 on the garage sale, then they got up to $200 on the car wash, how much money did they raised for the car wash? What we do is $200 - $1200= $600. We keep doing it that way on the others. 

The children's goal was to get $5000 but they only got up to $4200. So the rest of the $5000 must be paid by the 30 students. How much does each student have to pay? The answer is $26.70.