First before u solve it u want to make 2 5/8 a smaller fraction. To do that you will do 2x8+5. When u get that the number u get is the numerator and your bottom number will the same (8). After you do that you have to make the two fractions have the same bottom number so you will find a number they have in common using the times table. And wat u do to the bottom you do to the top. For an example 5/8 and 2/4 are two fractions to find two common denominators u will do 8*4 which gives you 32 so what u do to the bottom you do to the top fraction 1 5/8 will be 20/32 because 8*4 is 32 and 5*4 is 20 which gives you the fraction 20/32