Order of Operations
What does PEMDAS stand for?
P- Parentheses, E- Exponents, M- Multiplication, D- Division, A- Addition, S- Subtraction
Evaluate the expression when s = 3
18 ➗ s
= 6
Plug in 3 for the s, so the new expression is 18 ➗ 3
Tell whether the given number is a solution of the equation (Write yes or no)
7 + x = 10; 3
Yes
7 + 3 = 10
What is the first step of the problem solving plan?
Read and Understand
What is the first step in evaluating 3 + 5 x 8 - 7?
5 x 8, because multiplication comes before addition and subtraction.
Evaluate the expression
6 ➗ 3 x (3 + 1)
= 8
First, do the operation inside of the parentheses, which is 3 + 1 = 4. The new expression is 6 ➗ 3 x 4. Then, work from left to right because there is only multiplication and division left in the problem. 6 ➗ 3 = 2., and 2 x 4 = 8.
Evaluate the expression when a = 3
16 - a2
= 7
Plug in 3 for a, so the new expression is 16 - 32. Do the exponent, so 3 x 3 = 9. Now you have 16 - 9 = 7.
Tell whether the given number is a solution of the equation (Write yes or no)
9 - r = 8; 2
No
9 - 2 = 7 not 8
What is the second step of the problem solving plan?
Make a Plan
Evaluate the expression
4 + 2 x 3
= 10
2 x 3 = 6. 6 + 4 = 10.
Evaluate the expression
3 x (7 - 5) + 4
= 10
First, solve the parentheses. 7 - 5 = 2, so the new expression is 3 x 2 + 4. Next, you do 3 x 2 because multiplication comes before addition. 3 x 2 = 6. Lastly, add 6 + 4, which is 10.
Evaluate the expression when x = 6 and y = 3.
X - 18 ➗ y2
= 4
Plug in 6 and 3, so your new expression is 6 - 18 ➗ 32. First, do the exponents, so 3 x 3 = 9. The expression is now 6 - 18 ➗ 9. Then because multiplication comes before subtraction, you do 18 ➗ 9 = 2. Your new expression is 6 - 2, which = 4.
Solve using mental math
56 ➗ m = 7
M = 8
What is the third step of the problem solving plan?
Solve the Problem
Evaluate the expression
(6 + 4)2 - 8
= 92
First you do 6 + 4 = 10. Then you do 102, which is 100. Finally do 100 - 8, which is 92.
Evaluate the expression
8 + 42
= 24
First, do 42, which is 4 x 4 = 16. Your new expression is 8 + 16. Add them together and you get 24.
Evaluate the expression when x = 6 and y = 3.
3y - x
= 3
First, plug in 6 and 3 so your new expression is 3 x 3 - 6. Then, do 3 x 3, which = 9. Finally, do 9 -6, which = 3.
Solve using mental math
35 + a = 35
A = 0
What is the fourth step of the problem solving plan?
Look back and check your work
Evaluate the expression when r = 5
r x 9
= 45
5 x 9 = 45
You buy 3 rolls of gift wrap for $7 each, 4 rolls of ribbon for $3 each, and 5 packs of gift cards for $4 each. What is the total cost?
= $53 in total
First, multiply 3 x 7, which is 21. Then multiply 4 x 3, which is 12. Then multiply 5 x 4, which is 20. Finally, add 21 + 12 + 20 and get an answer of 53. Don't forget to label it with the dollar sign!
You receive a coupon for c dollars off a meal at a new restaurant. The expression 12 - c represents the cost of a $12 meal with a coupon. Use the expression to find out how much you pay when c = 5.
= $7
Plug in 5, so the new expression is 12 - 5, which is 7.
You earn $15 each time you mow your neighbor's lawn. Solve the equation d ➗ 4 = 15 to find the amount of money (d), you earn by mowing the lawn 4 times.
= $60
15 x 4 = $60
You went shopping with $25 and first spent $16. then you bought a $1 pen, a $5 game and a $2 magazine. How much money do you have left over?
= $1
Take $25 - $16, which is $9. Then subtract $1, which is $8. Then subtract $5, which is $3. Finally, subtract $2, leaving you with $1 left over.
Tell whether the statement is true or false. If false, find the correct answer.
13 x 0 = 13
False, 13 x 0 = 0.