What fraction is in between 3.5 and 3.6 on a number line?

The fraction that is in between 3.5 and 3.6 on a number line can be found by averaging the two numbers. To do this, add 3.5 and 3.6 together and divide by 2. This gives you (3.5 + 3.6) / 2 = 7.1 / 2 = 3.55. Therefore, the fraction in between 3.5 and 3.6 on a number line is 3.55.