Close

Some weeks back, we looked at some rounding rules. Today, let’s go over some official questions on rounding. They are quite simple and if we just keep the “Slip to the side and look for a 5” rule in mind, they can be easily solved.

Question 1: If and * is the decimal obtained by rounding to the nearest hundredth, what is the value of * – ?

(A) -0.0053

(B) -0.0003

(C) 0.0007

(D) 0.0047

(E) 0.0153

**Solution:** A quick note on place value nomenclature:

Given a decimal 345.789, we know that 5 represents the units digit, 4 the tens digit and 3 the hundreds digit. Also, 7 represents the tenths digit, 8 the hundredths digit and 9 the thousandths digit and so on…

Now let’s go back to this question:

We need to round to the nearest hundredth which means we will retain 2 digits after the decimal. The third digit after the decimal is 5 so 2.0453 rounded to the nearest hundredth is 2.05.

Thus *

Answer **(D)**.

Question 2: If digit is the hundredths digit in the decimal , what is the value of , rounded to the nearest tenth?

Statement 1:

Statement 2:

**Solution:** Given that

We need to find the value of rounded to the nearest tenth i.e. we need to keep only one digit after the decimal.

**Statement 1:**

In decimal form, it means

If were 5 or greater, would become 0.256 or 0.266 or higher. All these values would be more than 0.25 so must be less than 5 such as 0.246 or 0.236 etc. In all such cases, would be rounded to 0.2

This statement alone is sufficient.

**Statement 2:**

This is even simpler. Since we have been given that is less than 5, when we round to the tenths digit, we will get 0.2

This statement alone is also sufficient.

Answer **(D)**.

Question 3: If denotes a decimal number, is ?

Statement 1: When is rounded to the nearest tenth, the result is 0.5.

Statement 2: When is rounded to the nearest integer, the result is 1.

**Solution:** Again, a simple question!

We need to find whether is greater than or equal to 0.5 or not.

**Statement 1:** When is rounded to the nearest tenth, the result is 0.5.

This means that whatever is, when we round it to the nearest tenth, we get 0.5. What are the possible values of ? If is anywhere from 0.450 to 0.5499999…, it will be rounded to 0.5

Some of these numbers are less than 0.5 and others are greater than 0.5 so this statement alone is not sufficient.

**Statement 2:** When is rounded to the nearest integer, the result is 1.

In this case must be at least 0.5; only then can it be rounded to 1.

can be anything from 0.50 to 1.499999… In any case, will be greater than or equal to 0.5.

This statement alone is sufficient to answer the question.

Answer **(B)**.

We hope you see that if we just remember the rules, we can solve most rounding questions very quickly and efficiently.