Question

Find $385 \times 5 \times 20$ by suitable arrangement ?

Answer 1

Hint:For making the suitable arrangement first multiply those numbers which will give numbers like $10,100,1000,.........$ hence for this first do $5 \times 20$ and then the result which comes multiple with the $385$ .

Complete step-by-step answer:
As for the suitable arrangement we try to make the multiplication easier ,so in the given question $385 \times 5 \times 20$ .
hence for the suitable arrangement of this $385 \times 5 \times 20$
First multiply those numbers which will give numbers like $10,100,1000,.........$ by making $10,100,1000,.........$ this it will be easier to multiply with a third number and get the result .
So for the given question if we multiple $5 \times 20$ then the result came out is $100$ means that ,
$5 \times 20 = 100$ ,
Hence $100$ came , now the question converted as $385 \times 100$ this ,
Now it will easier to multiple the $385 \times 100$
the result will be $385 \times 100 = 38500$
Hence the answer will be $38500$ .

Note:If suitable arrangement is apply in addition then first add those numbers which will give the numbers whose units place is zero as for example if we add $837 + 208 + 63$ so for this as we see that $3 + 7 = 10$ mean that the unit place is ends with $0$ . So first we have to add $837 + 63$ the result came is $900$ Now the question is $208 + 900$ hence the answer is $1108$ .