Let's solve each problem step by step using the
order of operations, often remembered by the acronym
PEMDAS:
-
Parentheses
-
Exponents
-
Multiplication and
Division (from left to right)
-
Addition and
Subtraction (from left to right)
---
1. $ 18 - (21 - 5) \div (22 - 18) $
Step 1: Simplify inside parentheses:
- $ 21 - 5 = 16 $
- $ 22 - 18 = 4 $
So:
$ 18 - 16 \div 4 $
Step 2: Division:
- $ 16 \div 4 = 4 $
Step 3: Subtraction:
- $ 18 - 4 = 14 $
✔ Answer: 14
---
2. $ 24 \div 6 + 4 \times (3 + 6) $
Step 1: Parentheses:
- $ 3 + 6 = 9 $
So:
$ 24 \div 6 + 4 \times 9 $
Step 2: Multiplication and division (left to right):
- $ 24 \div 6 = 4 $
- $ 4 \times 9 = 36 $
Step 3: Addition:
- $ 4 + 36 = 40 $
✔ Answer: 40
---
3. $ 5 + 10 \times (3 - 2)^2 $
Step 1: Parentheses:
- $ 3 - 2 = 1 $
So:
$ 5 + 10 \times (1)^2 $
Step 2: Exponent:
- $ 1^2 = 1 $
So:
$ 5 + 10 \times 1 $
Step 3: Multiplication:
- $ 10 \times 1 = 10 $
Step 4: Addition:
- $ 5 + 10 = 15 $
✔ Answer: 15
---
4. $ (-7) + 2^3 \times 3 - 8 $
Step 1: Exponent:
- $ 2^3 = 8 $
So:
$ -7 + 8 \times 3 - 8 $
Step 2: Multiplication:
- $ 8 \times 3 = 24 $
So:
$ -7 + 24 - 8 $
Step 3: Left to right:
- $ -7 + 24 = 17 $
- $ 17 - 8 = 9 $
✔ Answer: 9
---
5. $ 8 \div [(-8) - (-2) + 5]^3 $
Step 1: Simplify inside brackets:
- $ -8 - (-2) = -8 + 2 = -6 $
- $ -6 + 5 = -1 $
So:
$ 8 \div (-1)^3 $
Step 2: Exponent:
- $ (-1)^3 = -1 $
So:
$ 8 \div (-1) = -8 $
✔ Answer: -8
---
6. $ 36 \div 3 \times [(7 - 2 - 4) \times 2] $
Step 1: Inside parentheses:
- $ 7 - 2 - 4 = 1 $
So:
$ 36 \div 3 \times [1 \times 2] $
Step 2: Simplify bracket:
- $ 1 \times 2 = 2 $
So:
$ 36 \div 3 \times 2 $
Step 3: Left to right:
- $ 36 \div 3 = 12 $
- $ 12 \times 2 = 24 $
✔ Answer: 24
---
7. $ 7 \times (4^2 + 2 - 8) $
Step 1: Exponent:
- $ 4^2 = 16 $
So:
$ 7 \times (16 + 2 - 8) $
Step 2: Inside parentheses:
- $ 16 + 2 = 18 $
- $ 18 - 8 = 10 $
So:
$ 7 \times 10 = 70 $
✔ Answer: 70
---
8. $ [8 - (-4) + (-8)]^2 \times 4 $
Step 1: Simplify inside brackets:
- $ 8 - (-4) = 8 + 4 = 12 $
- $ 12 + (-8) = 4 $
So:
$ [4]^2 \times 4 $
Step 2: Exponent:
- $ 4^2 = 16 $
So:
$ 16 \times 4 = 64 $
✔ Answer: 64
---
9. $ (81 \div 9) + 25 - 17 \times 2 $
Step 1: Parentheses and exponents:
- $ 81 \div 9 = 9 $
So:
$ 9 + 25 - 17 \times 2 $
Step 2: Multiplication:
- $ 17 \times 2 = 34 $
So:
$ 9 + 25 - 34 $
Step 3: Left to right:
- $ 9 + 25 = 34 $
- $ 34 - 34 = 0 $
✔ Answer: 0
---
10. $ (-2)^2 \div 4 - 9 \times 8 $
Step 1: Exponent:
- $ (-2)^2 = 4 $
So:
$ 4 \div 4 - 9 \times 8 $
Step 2: Multiplication and division (left to right):
- $ 4 \div 4 = 1 $
- $ 9 \times 8 = 72 $
So:
$ 1 - 72 = -71 $
✔ Answer: -71
---
✔ Final Answers:
1.
14
2.
40
3.
15
4.
9
5.
-8
6.
24
7.
70
8.
64
9.
0
10.
-71
Let me know if you'd like these explained in a different format!
Parent Tip: Review the logic above to help your child master the concept of mixed operations worksheet.