Equation Analysis and Solving Steps

The question asks us to find the value of the unknown number represented by a question mark ('?') in the given mathematical equation. The equation is:

$$225 \div 25 \times 9 - 3 \times ? = 60$$

To solve this, we need to follow the order of operations, commonly remembered by the acronym BODMAS/PEMDAS (Brackets, Order/Exponents, Division and Multiplication from left to right, Addition and Subtraction from left to right).

Step-by-Step Calculation

1. Division: First, perform the division operation from the left side of the equation: $$225 \div 25 = 9$$ The equation now becomes: $$9 \times 9 - 3 \times ? = 60$$
2. Multiplication: Next, perform the multiplication operation from the left: $$9 \times 9 = 81$$ The equation is now simplified to: $$81 - 3 \times ? = 60$$
3. Isolate the Unknown Term: To find the value of '$3 \times ?$', we need to rearrange the equation. Subtract 60 from both sides or move 60 to the left and '$3 \times ?$' to the right: $$81 - 60 = 3 \times ?$$ Calculate the difference: $$21 = 3 \times ?$$
4. Solve for '?': Finally, divide both sides by 3 to find the value of '?': $$\frac{21}{3} = ?$$ $$7 = ?$$

Final Answer Verification

Let's substitute the value 7 back into the original equation to verify:

$$225 \div 25 \times 9 - 3 \times 7$$ $$9 \times 9 - 3 \times 7$$ $$81 - 21$$ $$60$$

The result matches the right side of the original equation (60), confirming that our calculation is correct.

Therefore, the number that comes in place of the question mark is 7.