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Key
Idea
You can count
square units to find
the area of a figure. |
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Vocabulary
• area |
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Materials
• geoboard or
dot paper or
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Finding Area |
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How can you use counting to find the area of a shape? |
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When
you found the perimeter and circumference
of figures, you were finding the distance around
the figures. Area
is the number of square units
needed to cover a surface or figure. |
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You
can use a geoboard or dot paper to make
a shape and then count square units to find its
area. |
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Step
1 Make each of these figures on a
geoboard or draw them on dot paper. |
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2 Count the number of whole square
units and half square units each figure
covers to find its area. Record your results. |
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Step
3 On another piece of dot paper,
draw shapes with these areas: |
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| • 6 square units |
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| • 2 square units |
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square units |
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| a. |
What strategy did you use to find the areas?
Did you do the same thing for each figure? |
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| Sara counted all the |
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square units first and |
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the opposite. Did they get the same areas?
Why or why not? |
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| c. |
Reasoning Brianna looked at Figure C and said
she could find the area by subtracting 1 square
unit from 9 square units. Can you use a similar
process with any of the other figures? Explain. |
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