DAY 09

Comment

Find the difference between 6524 and 6531.

Answer

7.

Readers' methods

Alan W, Andover SP11:
I used a calculator to find a number that goes exactly into 6524 and 6531.
I started with 3, as 2 is obviously not a factor of both numbers.
I found that 7 goes into both numbers exactly.

Rona D:
The difference between 6524 and 6531 is 7
so the only number (apart from 1) which can be a factor of both must be 7.

David P, Southampton SO18:
I noticed that their difference is 7, divided them both by 7 and found that
6524/7 = 932 and so 6531/7 must be 933 because 6531 is 7 more than 6524.

Ian L, NP19:
If 6524 and 6531 have a second factor (apart from 1) then the difference
between the two numbers must be divisible by the factor.
As the difference is 7, which is a prime number, the only other factor apart from 1 is 7.

Angus M, Melrose TD6 9QE
The difference is 7 and 7 divides into both numbers. So the answer is 7.

Pupils from Holgate Comprehensive School, Hucknall, Nottinghamshire:
Difference is 6531 - 6524 = 7