Navigating through Measurement in Grades 3 – 5, NCTM, 2005
1
“Changing Garden”
FENCE
LENGTH
(Feet)
WIDTH
(Feet)
PERIMETER
(Feet)
AREA
(Square Feet)
A
1
14
30
14
B
2
13
30
26
C
3
12
30
36
D
4
11
30
44
E
5
10
30
50
F
6
9
30
54
G
7
8
30
56
2. What does
area
mean?
Area is the number of square units that cover a two-dimensional figure or
shape.
3. What does
perimeter
mean?
Perimeter is the distance around a two-dimensional figure or shape.
4. In the space below, use words, pictures, or numbers to describe how
you
would find the perimeter of a rectangle of any size.
Students’ responses will vary but should suggest the idea that they would (a)
add the lengths of all four sides, or (b) add the length and width of the
rectangle and multiply this sum by two, or (c) multiply the length by two and
width by two and add these two products.
5. Do all the possible gardens that use the 30 feet of wire fencing have
the same perimeter? _____________ Why, or why not?
Yes, all the gardens have the same perimeter. The changes in the
dimensions of each arrangement do not affect the total perimeter since at no
point does the total
amount
of fencing change.
6. Do all the possible gardens that use the 30 feet of wire fencing have
the same area? ______________ Why, or why not?
No, all the gardens do not have the same area. As the dimensionsl change,
square units are either “pulled into” or “pushed out of” the garden, changing
its area/ As the length and width approach each other in value (i.e. as the
garden becomes more nearly square), the space inside the garden, or its
area, increases.
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