Answer:
Percentage change in science projects = 20.93%
Step-by-step explanation:
Number of science projects last year = 43
Number of science project this year = 52
Change in science project or increase in science projects over last year
= 52 - 43
= 9
Now percentage increase or percentage change in science projects
= 
= 
= 20.93%
Therefore, percentage change in the number of science projects is 20.93%