3.MD.C.5.a: Know what a unit square is.

Official text

A square with side length 1 unit, called "a unit square," is said to have "one square unit" of area, and can be used to measure area.

What it means for your child

Your child learns that a square with sides of 1 unit is a 'unit square' and covers 1 square unit of area.

Try it at home

1. Cut out a 1-inch square and call it 'one square inch.'
2. Draw a 1-centimeter square on grid paper and compare it to a 1-inch square.
3. Ask, 'How many square inches do you think fit on this card?'