Part a) You have 1,000,000 number cubes, each measuring one inch on a side. If you stacked the cubes on top of one another to make an enormous tower, how high would they reach?
we know that
The high of one cube is equal to 1 in
so
to find the high of 1,000,000 cubes
Multiply the high of one cube by 1,000,000
so

therefore
the answer part a) is

Part b) If you arranged the cubes on the floor to make a square, would the square fit in your classroom? What would its dimensions be?
we know that
the area of a square is equal to

where
b is the length side of the square
so

the dimensions of the square would be 1,000 in x 1,000 in
convert to cm
we know that
1 in is-------> 2.54 cm
so
1,000 in=1,000*2.54=2,540 cm------> 25.40 meters
the dimensions of the square in meters would be 25.40 m x 25.40 m
It is possible that the square will fit in the classroom.