NZ Level 6 (NZC) Level 1 (NCEA)
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Estimate Area
Lesson

Estimating area

Sometimes we may only want an idea of the area of something, but it doesn't have to be exact. In that case, there are some techniques we can use to estimate area. In fact, some of the techniques are similar to how we estimate length.

Choosing the best option

Let's see in this video what we can do to choose between three possible answers for the area of our classroom wall.

Worked Examples

Question 1

Estimate the area of the artwork above the sofa if the sofa is $1.9$1.9m in length.

  1. $1.7$1.7 m2

    A

    $0.01$0.01 m2

    B

    $5$5 m2

    C

    $0.5$0.5 m2

    D

    $1.7$1.7 m2

    A

    $0.01$0.01 m2

    B

    $5$5 m2

    C

    $0.5$0.5 m2

    D

Working out an estimated area

This time, we're going to use the poster to help us work out an estimate for the area of the classroom wall. How can we use the measurements of the poster to help us? Watch the next video to find out. You'll also see how we can use grids to work out an estimated area.

Worked Examples

Question 2

Estimate the area of the curved shape below if each square on the grid has an area of $3$3 mm2.

  1. $111$111 mm2

    A

    $72$72 mm2

    B

    $26$26 mm2

    C

    $48$48 mm2

    D

    $111$111 mm2

    A

    $72$72 mm2

    B

    $26$26 mm2

    C

    $48$48 mm2

    D

Question 3

Estimate the area of the curved shape below if each square on the grid has an area of $3$3 mm2.

  1. $156$156 mm2

    A

    $192$192 mm2

    B

    $55$55 mm2

    C

    $135$135 mm2

    D

    $156$156 mm2

    A

    $192$192 mm2

    B

    $55$55 mm2

    C

    $135$135 mm2

    D

Remember!

There are different ways we can estimate area, so using what we know, thinking about what makes sense, and using grids and graphs are all great ways to work out an estimate.

Outcomes

GM6-1

Measure at a level of precision appropriate to the task

91032

Apply right-angled triangles in solving measurement problems

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