Question

The numbers 2.745 and 2.735 on rounding off to 3 significant figures will give ______.

Options

• 2.75 and 2.74

• 2.74 and 2.73

• 2.75 and 2.73

• 2.74 and 2.74

Answer 1

The numbers 2.745 and 2.735 on rounding off to 3 significant figures will give 2.74 and 2.74.

Explanation:

While rounding off measurements, we use the following rules by convention:

1. If the digit to be dropped is less than 5, then the preceding digit is left unchanged.
2. If the digit to be dropped is more than 5, then the preceding digit is raised by one.
3. If the digit to be dropped is 5 followed by digits other than zero, then the preceding digit is raised by one.
4. If the digit to be dropped is 5 or 5 followed by zeros, then the preceding digit is left unchanged if it is even.
5. If the digit to be dropped is 5 or 5 followed by zeros, then the preceding digit is raised by one if it is odd.

Units and Measurements:

Let us round off 2.745 to 3 significant figures.

Here the digit to be dropped is 5 and then the preceding digit is left unchanged if it is even.

Hence on rounding off 2.745, it would be 2.74.

Now consider 2.737, here also the digit to be dropped is 5 and then the preceding digit is raised by one if it is odd. Hence on rounding off 2.735 to 3 significant figures, it would be 2.74.