Imagine that you are planting flowers. The row is 68.5cm long. The plants should be 7cm apart. How many do you need. You know 68.5 is close to 70 and the plants should be 7cm apart and you know 70 divided by 7 is 10. So 10 plants should be enough. The reason why I rounded 68.5 because I needed to make the numbers easy to divide so I can get to answer that is close to what I need. If this example and my explaining did not help then I am sorry,