Answer:
Calculate the perimeter of rectangle whose side length is 7 feet and side width is 4 feet.
One way to get the answer, using the formula 2(w + L) = P
Layout your calculations neatly, so you can review, track changes, correct or learn from them. One way a layout can look is like this:
Get a $20orso dualdisplay scientific calculator, even if you can`t take it with you into the exam hall. A calculator is also a learning tool, Technology Use is one of the 9 Essential Skills you can`t do without.
Using a scientific calculator, do the following:
Enter 2
Press x (multiplication) button (this could be omitted, depending on your calculator`s circuits)
Press (
Enter 4
Press + button
Enter 7
Press )
Press =
You should see 22 on your display.
Calculate the perimeter of rectangle whose side length is 7 feet and side width is 4 feet.
Another way to get the answer, using the formula 2(w + L) = P:

Identify that the perimeter is to be calculated.

Recognize that the perimeter of a shape can be calculated by the formula 2(w + L).

Recognize that addition inside the bracket comes before multiplication by 2.

So, let`s set up the problem to work inside the bracket:
length + width = half the perimeter

Calculate: 7 + 4 = 11

Take a pencil and write down “half the perimeter = 11” or “P/2 = 11”
1 length + 1 width goes around the rectangle only halfway around. The other half needs to be counted as well.

Set up to finish the rest of the problem outside the bracket:
2 x half perimeter = perimeter

Calculate: 2 x 11 = 22

Take a pencil and write down “perimeter = 22” or “P = 22”

Write ft or ` sign or feet after the number 22 Now you`re done with the math.

The last step: check your work, make sure everything was copied and written correctly then determine that the correct way to write the answer is 22 ft or 22` or 22 feet
Another way to get the answer, using only addition:

Identify that the perimeter is to be calculated.

Recognize that the perimeter of a shape can be calculated by addition.

Set up the problem:
length + width + length + width = perimeter

Calculate: 7 + 4 + 7 + 4 = 22

Take a pencil and write down “perimeter = 22” or “P = 22”

Write ft or ` sign or feet after the number 22 Now you`re done with the math.

The last step: check your work, make sure everything was copied and written correctly then determine that the correct way to write the answer is 22 ft or 22` or 22 feet
ADVANCED

Compare step 3 in episodes 10 & 11. Perimeter is said to be calculated by
“length + width + length + width” in one and
“length + length + length + length” in the other
One includes “width” the other does not. The formulas look different. But they are really not.
Why? Is there still a way that explains how these 2 different formulas are the same, consistent and valid? Look for clues in episode 09.

Words in English can not be meaningfully written backwards. For example:
MATH is meaningful, HTAM is not.
Formulas in math can be written backwards. The formula used in the problem is
2(w + L) = P , same as P = (w + L) x 2
just written backwards.
A formula is a symbolic shorthand way to write procedures. Based on either of these formulas the 2step procedure in full words looks like:
“Start inside the bracket with the WIDTH, then add LENGTH to it. This total will be doubled to come to the final result.”

What if you take the LENGTH first (7ft), then add WIDTH to it (4ft), then double their sum to get perimeter. Does the final answer change? Write the last sequence into a formula.

Compare the steps in 2) and 3) above with this formula:
P = 2W + 2L
In words, this formula reads:
Double the width, then double the length, then add their totals together to get perimeter. “
If L = 7 ft and w = 4 ft, does this formula P = 2W + 2L get the same results as 2(w + L) = P ?

Write an equation from these words: Double the length, then double the width, add them together to get perimeter.

The perimeter of a square is P = 4s

What do you think “s” stands for?

How is the square`s formula similar and different from a rectangle`s? List similarities and differences.

Addition is commutative. So is multiplication. Definition of “commute” from a dictionary tells us that “commute = travel some distance between one's home and place of work, travel to and from work, travel to and fro, travel back and forth”
a) So, what does commutative mean in math?
b) Write an example using the numbers 2 and 3 showing that addition is commutative.
c) Write an example that multiplication is commutative, using the numbers 2 and 3.

So now we have at least 6 possible ways to calculate the perimeter of a rectangle:
2L + 2W = P
2W + 2L = P
(L + w) x 2 = P
(w+ L) x 2 = P
and using only addition
L + w + L + w = P
w + L + w + L = P
Same results, about the same number of steps, same amount of work. Use a formula that`s easiest to remember for you.
ANSWERS:

Length and width are synonyms, interchangeable. Their precise meaning depends on the point of view of the observer.

Result does not change. (L + w) x 2 = P

Yes

2L + 2W = P

a) side length
b) DIFFERENCES:
To calculate the square`s perimeter there is just one number to work with (s). There`s neither length or width to work with.
To calculate the rectangle`s perimeter, you have to have 2 numbers for length and width, 1 number is not enough.
SIMILARITIES: Both perimeters also possible to calculate by addition only
Square P = s + s + s + s
Rectangle P = L + w + L + w
or both shapes can be calculated faster by using multiplication instead of only addition:
Square P = 4s
Rectangle P = 2(L+W)

a) The numbers can change their order, the terms are interchangeable
b) 2 + 3 = 3 + 2
c) 2 x 3 = 3 X 2