Hi! I'm happy to help!
First you will need to split your line into the appropriate number of divisions. Because the fraction has a denominator (bottom) of 8, we split into 8 divisions. From there you count up from zero to 7, because it is 7/8.
0 is 0, the next dash is one, the next is two, and so on. The number one should be 8. Place the marker on the one that counts as 7.
I hope this was helpful, keep learning! :D
