How do kids learn volume in 5th grade?
Volume is how many unit cubes fit inside a solid. Kids count the cubes in one layer (length × width), then multiply by the number of layers (height). That is where the volume formula V = length × width × height comes from.
How you probably learned it
You probably learned V = l × w × h as a formula to plug numbers into.
How your kid is learning it
Your kid builds boxes out of cubes first. A box 4 long and 3 wide has 12 cubes in the bottom layer, and 2 layers make 24 cubes. The formula comes from that picture, so it makes sense.
Base area times height
Kids also learn V = B × h, where B is the area of the base (the bottom layer). If the base is 12 square feet and the box is 5 feet tall, the volume is 12 × 5 = 60 cubic feet.
Shapes made of two boxes
For an L-shaped figure, split it into two boxes, find each volume, and add them. Volume adds up, just like area.
