Let’s evaluate each numerical expression step by step:

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1. $15.5 \times [(2 \times 2.4) + 3.2] - 24$

1. Solve inside the brackets first: $2 \times 2.4 = 4.8$ $4.8 + 3.2 = 8$
2. Multiply: $15.5 \times 8 = 124$
3. Subtract 24: $124 - 24 = 100$ Answer: 100

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2. $34 \div [(7.2 \times 0.8) + 3.24]$

1. Solve inside the brackets: $7.2 \times 0.8 = 5.76$ $5.76 + 3.24 = 9$
2. Divide: $34 \div 9 = 3.777\ldots \ (\text{or } 3.78 \text{ rounded to 2 decimals})$ Answer: 3.78

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3. $4.4 + [4 \times 14 + 8.6]$

1. Solve inside the brackets: $4 \times 14 = 56$ $56 + 8.6 = 64.6$
2. Add: $4.4 + 64.6 = 69$ Answer: 69

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4. $[6 \times (3 \times 8.3)] + 1.6$

1. Solve the inner multiplication first: $3 \times 8.3 = 24.9$ $6 \times 24.9 = 149.4$
2. Add 1.6: $149.4 + 1.6 = 151$ Answer: 151

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Do you want further clarifications or additional examples?
Here are 5 related questions to delve deeper:

1. Can you evaluate nested brackets with more terms?
2. How do rounding rules apply to decimals in intermediate steps?
3. How does the order of operations affect results in longer expressions?
4. What happens if parentheses are misplaced in expressions?
5. How do you simplify expressions with multiple variables?

Tip: Always follow the PEMDAS/BODMAS order to avoid errors in calculations.