Question

Question 2(d)

Find the product by suitable arrangement:

$625\times 279\times 16$

Answer 1

We can arrange the calculation in such a way that it becomes easy and quick to find the answer.

$625\times 279\times 16$

We need to arrange it in such a way that the product of any two of the numbers given must have zeros in its last digits, preferably a multiple of 10, like 100 or 1000 or 10,000. Just by looking at the last digits of each number we can spot that 625 and 16 would give a product that has zero in its last digit. It just happens to be that $16\times 625$ = 10,000.
= $(625\times 16)\times 279$

Now the product of 10,000 and 279 becomes very easy as :
= $10000\times 279$

= 2790000