Sure, we'll start off by simplifying the ratio 2:8. Simplifying it gives us 1:4.
Our aim is to find a number, let's denote it by x, such that the ratio 2:x will be the same as 1:4.
To find such an x, we need to set up an equation using the principle of equivalence of ratios. This gives us 2/x = 1/4.
Now we proceed to solve this equation for x. We do this by cross-multiplying the fractions in the equation.
Cross-multiplication gives us 2*4 = x*1. Simplifying this yields 8 = x.
Hence, we can conclude that the number x that makes the ratio 2:x equivalent to 2:8 is 8.