Answer:
For (a) the answer is 450, 50(9)=450 total blocks.
Explanation:
For (c), you will have to use a scale of 1 to 5, so, 450(5)=2,250.
For (b), if the map is 21 square inches and you want to enlarge it to the size you want, you would have to take the total value of the original map and multiply it by whatever factor it has to be multiplied by.
Now finally for (d), I applied proportional reasoning by looking at the dimensions and adding them all together to get the area value, then comparing the area value to the enlarged figure or decreased figure.
(I did this quite a long while ago, I'm going based on my memory and math skills, sorry if I failed horrendously.)