To solve the problems using the
order of operations, we follow the PEMDAS/BODMAS rule:
-
Parentheses/Brackets
-
Exponents/Orders (powers and square roots, etc.)
-
Multiplication and
Division (from left to right)
-
Addition and
Subtraction (from left to right)
Let's solve each problem step by step.
---
a) \( 3 \times 5 + 6 \)
1. Perform multiplication first:
\[
3 \times 5 = 15
\]
2. Then perform addition:
\[
15 + 6 = 21
\]
Answer:
\[
\boxed{21}
\]
---
b) \( 7 + 8 - 2 - 1 + 2 - 5 \)
1. Perform all additions and subtractions from left to right:
\[
7 + 8 = 15
\]
\[
15 - 2 = 13
\]
\[
13 - 1 = 12
\]
\[
12 + 2 = 14
\]
\[
14 - 5 = 9
\]
Answer:
\[
\boxed{9}
\]
---
c) \( 7 \times 3 - 2 \times 4 + 1 \)
1. Perform multiplications first:
\[
7 \times 3 = 21
\]
\[
2 \times 4 = 8
\]
2. Substitute back and perform addition/subtraction from left to right:
\[
21 - 8 = 13
\]
\[
13 + 1 = 14
\]
Answer:
\[
\boxed{14}
\]
---
d) \( 7 + (4 \times 5 - 3) - 2 \times 3 \)
1. Solve the expression inside the parentheses first:
\[
4 \times 5 = 20
\]
\[
20 - 3 = 17
\]
2. Substitute back and perform the remaining multiplications:
\[
2 \times 3 = 6
\]
3. Substitute back and perform addition/subtraction from left to right:
\[
7 + 17 = 24
\]
\[
24 - 6 = 18
\]
Answer:
\[
\boxed{18}
\]
---
e) \( 2 \times 3 \times 9 \div 3 - 2 \)
1. Perform multiplications and divisions from left to right:
\[
2 \times 3 = 6
\]
\[
6 \times 9 = 54
\]
\[
54 \div 3 = 18
\]
2. Then perform subtraction:
\[
18 - 2 = 16
\]
Answer:
\[
\boxed{16}
\]
---
f) \( 42 \div 7 + 3 \times 6 \)
1. Perform division and multiplication first:
\[
42 \div 7 = 6
\]
\[
3 \times 6 = 18
\]
2. Then perform addition:
\[
6 + 18 = 24
\]
Answer:
\[
\boxed{24}
\]
---
g) \( 4 \times (9 - 4) + (3 + 28 \div 7) \times 2 - 8 \)
1. Solve the expressions inside the parentheses first:
\[
9 - 4 = 5
\]
\[
28 \div 7 = 4
\]
\[
3 + 4 = 7
\]
2. Substitute back and perform multiplications:
\[
4 \times 5 = 20
\]
\[
7 \times 2 = 14
\]
3. Substitute back and perform addition/subtraction from left to right:
\[
20 + 14 = 34
\]
\[
34 - 8 = 26
\]
Answer:
\[
\boxed{26}
\]
---
Final Answers:
\[
\boxed{21, 9, 14, 18, 16, 24, 26}
\]
Parent Tip: Review the logic above to help your child master the concept of order of operations worksheet 4th grade.
