How to estimate 75×5?
The Correct Answer and Explanation is :
To estimate (75 \times 5), we can round the numbers to make the calculation easier. The number (75) is close to (80), which is a multiple of (10), making it simpler to multiply. Therefore, we can estimate:
[
75 \approx 80
]
Now, we can multiply:
[
80 \times 5 = 400
]
Thus, the estimated answer for (75 \times 5) is approximately (400).
To find the exact answer, we can calculate it directly:
[
75 \times 5 = 375
]
Now, let’s discuss the reasoning behind estimation. Estimation is a useful mathematical skill that helps in quickly assessing the magnitude of a number without needing to perform exact calculations. It allows us to make quick judgments, check the plausibility of our calculations, or decide whether a detailed computation is necessary.
When estimating, we often round numbers to make the math simpler. This can involve rounding to the nearest ten, hundred, or other significant figure, depending on the context. In our case, rounding (75) up to (80) is appropriate because it’s relatively close, making mental multiplication easier.
Estimation is particularly valuable in real-world applications, such as budgeting, shopping, or any situation where quick calculations are beneficial. For example, when shopping, if you know the prices of items, estimating the total cost can help you stay within your budget without needing to calculate the exact amount.
In conclusion, while (75 \times 5) gives an exact answer of (375), estimating it as (400) can provide a quick reference point and is an effective strategy in various practical situations.