Problem: Solve the given expressions using a calculator, following the correct order of operations and utilizing the appropriate buttons for powers and brackets.
####
Expressions to Solve:
1. \( (154 + 146) \div (79 + 71) \)
2. \( (3.5 \times 12) - (4.2 + 3.8) \)
3. \( 15^2 \)
4. \( 6^3 - 5^2 \)
5. \( (5 + 3)^2 - (5 - 2)^3 \)
6. \( 3.6^2 - 1.8^2 \)
7. \( (70 \div 3.5)^2 - 400 \)
---
Solution:
####
a) \( (154 + 146) \div (79 + 71) \)
1.
Step 1: Calculate the sum inside the first bracket:
\[
154 + 146 = 300
\]
2.
Step 2: Calculate the sum inside the second bracket:
\[
79 + 71 = 150
\]
3.
Step 3: Divide the results:
\[
300 \div 150 = 2
\]
Answer:
\[
\boxed{2}
\]
---
####
b) \( (3.5 \times 12) - (4.2 + 3.8) \)
1.
Step 1: Calculate the product inside the first bracket:
\[
3.5 \times 12 = 42
\]
2.
Step 2: Calculate the sum inside the second bracket:
\[
4.2 + 3.8 = 8
\]
3.
Step 3: Subtract the results:
\[
42 - 8 = 34
\]
Answer:
\[
\boxed{34}
\]
---
####
c) \( 15^2 \)
1.
Step 1: Use the "square" button on the calculator:
\[
15^2 = 225
\]
Answer:
\[
\boxed{225}
\]
---
####
d) \( 6^3 - 5^2 \)
1.
Step 1: Calculate \( 6^3 \):
\[
6^3 = 6 \times 6 \times 6 = 216
\]
2.
Step 2: Calculate \( 5^2 \):
\[
5^2 = 5 \times 5 = 25
\]
3.
Step 3: Subtract the results:
\[
216 - 25 = 191
\]
Answer:
\[
\boxed{191}
\]
---
####
e) \( (5 + 3)^2 - (5 - 2)^3 \)
1.
Step 1: Calculate the sum inside the first bracket:
\[
5 + 3 = 8
\]
2.
Step 2: Square the result:
\[
8^2 = 64
\]
3.
Step 3: Calculate the difference inside the second bracket:
\[
5 - 2 = 3
\]
4.
Step 4: Cube the result:
\[
3^3 = 3 \times 3 \times 3 = 27
\]
5.
Step 5: Subtract the results:
\[
64 - 27 = 37
\]
Answer:
\[
\boxed{37}
\]
---
####
f) \( 3.6^2 - 1.8^2 \)
1.
Step 1: Calculate \( 3.6^2 \):
\[
3.6^2 = 3.6 \times 3.6 = 12.96
\]
2.
Step 2: Calculate \( 1.8^2 \):
\[
1.8^2 = 1.8 \times 1.8 = 3.24
\]
3.
Step 3: Subtract the results:
\[
12.96 - 3.24 = 9.72
\]
Answer:
\[
\boxed{9.72}
\]
---
####
g) \( (70 \div 3.5)^2 - 400 \)
1.
Step 1: Calculate the division inside the bracket:
\[
70 \div 3.5 = 20
\]
2.
Step 2: Square the result:
\[
20^2 = 20 \times 20 = 400
\]
3.
Step 3: Subtract 400:
\[
400 - 400 = 0
\]
Answer:
\[
\boxed{0}
\]
---
Final Answers:
\[
\boxed{2, 34, 225, 191, 37, 9.72, 0}
\]
Parent Tip: Review the logic above to help your child master the concept of calculator practice worksheet middle school.
