**Question**: How many additional blocks to make the cube whole? or How many cubes are missing to build a full cube

**Answer**: So, it’s a “cube” that’s 5 x 5 x 4

100 blocks total.

Bottom row 5 x 4 =20

Next row 4 x 4 =16

Next row 3 x 4 =12

Next row 2 x 4 =8

Top row 2 x 4 =8

Total 64

Missing 100 – 64 = 36

To make a perfect 5 x 5 x 5 cube, add one more row

5 x 5 =25

25 + 36 = 61