Peter has 4 boxes of markers.
Each box has 8 markers in it.
He adds 1 more marker to each box.

33 markers

Step-by-step explanation:

lets give them symbols first:

x=markers

4x because there are 4 boxes for markers and we don't know if there is any markers so we say X for it.

Next, we do know how many markers, there are 8 markers, so we replace the x with 8

4(8) this means we have to multiply so 4 times 8 is 32.

Then it says he adds 1 marker in each of the boxes.

remember that there are 4 boxes.

4(1) is 4 times 1 which is 4

So, simply do 32+4= 36

:)

b. astronomers