1x1 Square with an area of 1 square unit

2x2 Square with an area of 4 square units

Six by Six Square Grid

1x2 Square with an area of 2 square units

Possible

4 + 4 Two ways

4 + 2 + 2 Four ways

4 + 2 + 1 + 1 Zero ways

4 + 1 + 1 + 1 + 1 One way

2 + 2 + 2 + 2 Five ways

2 + 2 + 2 + 1 + 1 Twenty Ways

2 + 2 + 1 + 1 + 1 + 1 Fourteen Ways

2 + 1 + 1 + 1 + 1 + 1 + 1 ways

1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 Two ways

48

90 ways?