6th grade Q3

To measure the surface area of solid shapes, you use square units, just like when measuring the area of plane figures.

For example, if you count all the squares covering all six sides of this prism, you would find that its surface area is 90 square units.

To specify how large each square is, you need to include units. Here’s how it works:

• 1 square centimeter is a square with side lengths of 1 cm. It is written as: $1{\text{ cm}}^2$. ${\text{cm}}^2$ is used for measuring small objects, like the area of a photograph.
• 1 square meter is a square with side lengths of 1 m. It is written as: $1{\text{ m}}^2$.  ${\text{m}}^2$ are used for measuring larger objects, like the floor area of a room.
• 1 square inch is a square with side lengths of 1 in. It is written as: $1{\text{ in}}^2$.
• 1 square foot is a square with side lengths of 1 ft. It is written as: $1{\text{ ft}}^2$.
• 1 square kilometer is a square with side lengths of 1 km. It is written as: $1{\text{ km}}^2$.

Example:

Let’s say you have a small cube, and each side of the cube is 1 inch long. To find the surface area of the cube, you follow these steps:

1. Count the faces: A cube has 6 faces.
2. Calculate the area of one face: Each face is a square with a side of 1 in. So, the area of one face is:

3. Multiply to find the total surface area: Since the cube has 6 faces, you multiply the area of one face by 6:

So, the surface area of a cube that measures 1 in on each side is 6 square inches, $6{\text{ in}}^2$.