If '+' means '-', '-' means ' ÷', '×' means '+' and ' ÷ ' means '×', then what will be the value of the expression 13 + 6 ÷ 2 × 32 - 2?
17
This problem requires us to evaluate a given mathematical expression after changing the meaning of the arithmetic symbols according to specific rules. We need to carefully substitute the symbols and then calculate the value of the new expression following the standard order of operations.
The rules for changing the meaning of symbols are as follows:
The original expression provided is:
\(13 + 6 \div 2 \times 32 - 2\)
Now, let's replace each symbol in the original expression with its new meaning as per the given rules:
So, the expression transforms from \(13 + 6 \div 2 \times 32 - 2\) to:
\(13 - 6 \times 2 + 32 \div 2\)
Now we evaluate the new expression \(13 - 6 \times 2 + 32 \div 2\). We must follow the order of operations, commonly remembered by acronyms like BODMAS or PEDMAS.
In our expression \(13 - 6 \times 2 + 32 \div 2\), we have Subtraction, Multiplication, Addition, and Division. Following BODMAS/PEDMAS, we perform Division and Multiplication first, from left to right, and then Addition and Subtraction from left to right.
After applying the symbol substitutions and evaluating the expression according to the order of operations, the final value is 17.
| Step | Operation | Expression | Result |
|---|---|---|---|
| Original | Substitution Rules Applied | \(13 + 6 \div 2 \times 32 - 2\) | \(13 - 6 \times 2 + 32 \div 2\) |
| 1 | Division (\(32 \div 2\)) | \(13 - 6 \times 2 + 16\) | 16 |
| 2 | Multiplication (\(6 \times 2\)) | \(13 - 12 + 16\) | 12 |
| 3 | Subtraction (\(13 - 12\)) | \(1 + 16\) | 1 |
| 4 | Addition (\(1 + 16\)) | \(17\) | 17 |
Here’s a quick table summarizing the key steps when tackling symbol substitution problems:
| Action | Description |
|---|---|
| Understand Rules | Note down exactly what each original symbol means after substitution. |
| Rewrite Expression | Carefully replace each original symbol in the expression with its new meaning. Double-check this step. |
| Apply Order of Operations | Evaluate the new expression strictly following BODMAS/PEDMAS (Brackets, Orders, Division/Multiplication, Addition/Subtraction). |
| Calculate Step-by-Step | Perform operations one at a time, simplifying the expression in stages to avoid errors. |
The order of operations is crucial in mathematics to ensure that everyone gets the same answer when evaluating an expression. Without a standard order, different people might perform calculations in a different sequence and arrive at different results. BODMAS (or PEDMAS) provides this standard sequence:
In symbol substitution problems, once the symbols are changed, applying this standard order is key to finding the correct value of the resulting expression.
Which two numbers should be interchanged to make the given equation correct?
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Which of the following interchange of numbers and mathematical signs would make the given equation correct?
30 ÷ 6 × 4 + 15 - 35 = 25
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23 + 84 ÷ 14 × 8 − 3 = 5
Select the correct combination of mathematical signs that can sequentially replace the * signs and make the equation correct.
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