Please see below a question on my 11 year old daughter's exam paper that we have no idea of the answer.
Find two numbers which when multiplied together make a thousand. neither of the two numbers must use any zeros.
Then, find two numbers which when multiplied together make a million. again neither of the two numbers must use any zeros.
Is there a quick way to do this rather then guess numbers a multiply them?
I suppose that we talk about positive integer numbers.
Divide up 1000 into prime numbers:
1000 = 10*10*10 = 2*2*2*5*5*5.
We have to componate two groups so that the two numbers have not any zeros. Zero will appear if the number containts 2 and 5 together. Therefore the one number = 2*2*2 the other = 5*5*5.