A square with a side of 5 cm was cut from a rectangle with sides of 10 and 8 cm. Find the area of the remaining part.

If the sides of the rectangle were 10 cm and 8 cm, then we determine the area of the rectangle.

You need to use multiplication.

10 cm * 8 cm = 80 cm² – the area of the specified rectangle.

If the side of the cut out square is 5 cm, then we determine its area.

5 cm * 5 cm = 25 cm² – equal to the area of the square.

In order to find the rest after the square was cut out of the rectangle, you need to subtract the area of the square from the area of the rectangle.

80 cm² – 25 cm² = 55 cm² – equal to the area of the remaining part.