rying to verify the volume of a rectanguler prism

h=10 inches
w=2
and the formula to find the volume is l.w.h
not a math genius just trying to make sure i am calculating this correctly

to find the lengh we had to divide the width of the prism so 2 inches divided by 4 =0.5 which pretty much is 1/2
1x1x10=10
2x2x1=4 =2.5
10 divided 2.5=4

I'm not sure how you found the length given only the height and width. Why divide by 4? Were you also given the volume?