Round off the following number to 3 significant digits-
(i) 899.68
(ii) 987.52
(iii) 2.0082
(iv) 336.5
(v) 335.5

Answer

To round off the given numbers to three significant digits, we will follow these steps:

### Step 1: Identify the first three significant digits.
- Significant digits are the first non-zero digits in a number, counting from left to right.

### Step 2: Look at the digit immediately following the third significant digit.
- This digit will determine whether we round up or keep the third significant digit as is.

### Step 3: Apply rounding rules.
- If the digit is 5 or greater, we round up the third significant digit by one.
- If the digit is less than 5, we leave the third significant digit unchanged.

### Step 4: Write the final rounded number.

Now, let's apply these steps to each of the provided numbers:

#### (i) 899.68
1. The first three significant digits are 8, 9, and 9.
2. The next digit is 6 (after 899).
3. Since 6 is greater than 5, we round up the last significant digit (9) to 10, which increases the second significant digit (9) by 1.
4. Therefore, 899.68 rounded to three significant digits is **900**.

#### (ii) 987.52
1. The first three significant digits are 9, 8, and 7.
2. The next digit is 5 (after 987).
3. Since 5 is equal to 5, we round up the last significant digit (7) to 8.
4. Therefore, 987.52 rounded to three significant digits is **988**.

#### (iii) 2.0082
1. The first three significant digits are 2, 0, and 0.
2. The next digit is 8 (after 2.00).
3. Since 8 is greater than 5, we round up the last significant digit (0) to 1.
4. Therefore, 2.0082 rounded to three significant digits is **2.01**.

#### (iv) 336.5
1. The first three significant digits are 3, 3, and 6.
2. The next digit is 5 (after 336).
3. Since 5 is equal to 5, we do not round up the last significant digit (6).
4. Therefore, 336.5 rounded to three significant digits is **336**.

#### (v) 335.5
1. The first three significant digits are 3, 3, and 5.
2. The next digit is 5 (after 335).
3. Since 5 is equal to 5, we do not round up the last significant digit (5).
4. Therefore, 335.5 rounded to three significant digits is **335**.

### Final Answers:
1. 899.68 → **900**
2. 987.52 → **988**
3. 2.0082 → **2.01**
4. 336.5 → **336**
5. 335.5 → **335**