We have two responses for you.

Hi Raymond,

What you are working with here is what is called equivalent fractions, meaning the second fraction is just a multiple of the first. 

In order to solve the question, you need to first ask yourself what operation was done to the 8 to change it to 16.  Once you have this answer, you can then perform the same operation to the 5 to find the question mark.

For example, if I have the following question:

I first ask myself, what operation was done to the 7 to change it to 28.  Obviously, 7 is multiplied by 4 to become 28.  Knowing this, we simply multiply 3 by 4, which gives us 12.  This is now replaced for the question mark.

Sara

Hi Raymond,
In order to find a fraction equivalent (the same size) to the one you were given, you must perform the same operation to the numerator (top number) and denominator (bottom number). Try this example:

1/2=?/8

We can see that 2 must have been multiplied by 4 in order to get 8 (4*2=8) by dividing 8 by 2 (8/2=4). So we must multiply the numerator by the same number in order to have an equivalent fraction.

1/2 * 4/4 = 4/8

Because 4/4 is really 1, we aren't really changing the value, just the way we write it.
Melanie