Question

Round 691 to 1 significant figure!

Answer 1

Rounding to 1 significant figure means writing the number with only 1 non-zero figure.

Thus rounding 691 to 1 significant figure, means writing 691 as 700.


Answer: 700


Remark: if we were asked to round to 2 significant figure, we would round the number as 690

Answer 2

The correct answer is: 700

Explanation:

In order to round to 1 significant figure, ALWAYS REMEMBER, we will look at the first digit of the number, and make sure that it is not zero (zero case will be discussed at the end, as in this particular example zero is not the first digit).

In 691, the first digit at hundredth place is 6. Now we will look at the next digit. In this case, the next digit is 9, which is greater than 5, therefore, the 6 will round off to 7, and rest of the digits will become zero to round it off to one significant figure. Hence, the answer is 700.

(EXTRA INFORMATION) Zero case:

If we have the following number: 0.951. Now the first digit is 0, but as there is a decimal point after that, therefore, it is insignificant. We will move on to the first digit after the decimal point, which is 9 in this case. Now, we will look at the next number. In this case it is 5, therefore, 0.951 is closer to 1.0 after rounding off. Hence, in this case the answer will be 1.0.