Any number divided by 1 is still that number (it stays the same).
So you can rewrite 280 as 280/1, which is a fraction.
With 280/1, you can also get an equivalent fraction by multiplying the numerator and denominator by a number, let's say 2.
So multiplying the numerator 280 by 2 would get 560, the denominator would be 2. So another equivalent fraction would be 560/2
