Answer :

To round each number to two significant figures, follow these steps:

1. Identify the first two significant figures.
2. Round the number appropriately based on the value of the third digit.

Let's address each number one by one:

(a) 0.436

- The first two significant figures are 4 and 3.
- The third digit is 6, which is greater than 5. So, round the second digit up by 1.

Thus, 0.436 rounded to two significant figures is 0.44.

(b) 9.000

- The first significant figure is 9.
- Since the number has trailing zeros, they are not counted beyond the significant figures.

Thus, 9.000 rounded to two significant figures is 9.0.

(c) 27.2

- The first two significant figures are 2 and 7.
- The third digit is 2, which is less than 5, so the second digit remains unchanged.

Thus, 27.2 rounded to two significant figures is 27.

(d) 135

- The first two significant figures are 1 and 3.
- The third digit is 5, indicating rounding up the second digit.

Thus, 135 rounded to two significant figures is 140 (since 1.4 × 10^2 = 140).

(e) \(1.497 \times 10^{-3}\)

- The first two significant figures are 1 and 4.
- The third digit is 9, which is greater than 5, so the second digit is rounded up by 1.

Thus, \(1.497 \times 10^{-3}\) rounded to two significant figures is 0.0015.

(f) 0.445

- The first two significant figures are 4 and 4.
- The third digit is 5, indicating rounding up the second digit.

Thus, 0.445 rounded to two significant figures is 0.45.

So the final results are:
- (a) \(0.44\)
- (b) \(9.0\)
- (c) \(27\)
- (d) \(140\)
- (e) \(0.0015\)
- (f) [tex]\(0.45\)[/tex]