Hey sealed rectangle or box measuring 8 x 6 x 18 contains 864 sugar cubes each measuring one by one by one how many sugar cubes are touching the box

The Total Volume is V= 8x6x18 = 864 units³ , Or 864 sugar cubes.
If we calculate V₁, the volume (or number of sugar cubes) that DOESN'T touch the sides of the box, then: V-V₁ = will give the volume (or the Cube number) of those who touch the box.

The following is in respect of the cubes that DO NOT touch the box:

The Length = 8, (or 8 cubes), becomes 6 (or 6 cubes), because already 
1 is touching at the right and another is touching at the left.

The Width = 6 , (or 6 cubes), becomes 4 (or 4 cubes), because already 
1 is touching at the right and another is touching at the left.

Same for the height = 18, it becomes 18-2 = 16, hence volume of the cubes that DON'T touch the box = V₁ = (8-2)(6-2)(18-2) = 384 Sugar cube

Then V-V₁ = 864 - 384 = 480 sugar cubes that TOUCH the box

38+105= 143, 39+104=143, and you will find then adding the numbers on opposite sides, moving inwards yields the answer 138 every time. because of this, you’re going to multiply 138 times the number of pairs, which is 34. therefore, 34*138= 4692(i’m sorry if it’s the wrong numbers, but it’s the right concept)