Question

Which of these procedures is the same as multiplying a whole number by 1,000?

- add 1,000 to the whole number three times

- multiply the whole number by three, ten times

- move the decimal point three places to the left and fill the blank spaces with zeros

- move each digit a whole number three places to the left and fill the blank spaces with zeros

Answer 1

The 4 one

Explanation:

Answer 2

The correct answer is D

Explanation:

For discarding the first three options, we take a counterexample which contradicts all first three procedures :

Let the whole number be 4. Then 4 × 1000 = 1000

(a). It says add 1000 to whole number 3 times

⇒ 4 + 1000 + 1000 +1000 = 3004 ≠ 3000 . So, discarded

(b). It says multiply the whole number by three, ten times

⇒ 4 × ( 3 × 3 × .......×3 ) ten times = 236196 ≠ 4000. So, discarded

(c). It says to move the decimal point to three places left.

⇒ 4 . _ _ _ and fill these blank space with zero

⇒ 4 . 0 0 0 = 4 ≠ 4000. So, discarded

(d). For this case let xy be any whole number where y is ones digit and x is tens digit.

Now, it says to move each digit of the number to three places left

⇒ x y _ _ _ and fill these blank spaces with zero

⇒ x y 0 0 0 = xy000 and multiplying the whole number xy with 1000 also gives xy000

So, it means the same if we do the procedure D.

Hence the right answer is D. move each digit a whole number three places to the left and fill the blank spaces with zeros.