[Joe Ross]

The trick is that you don't want to add 5 and 5 together repeatedly, becasue the answer is always 10. You want to add 5 to the result of the previous calculation. To do this you need to remember the previous calculation. In LabVIEW, there are two structures that remember a value from a previous loop, they are a feedback node and a shift register.

If you use one of those, you should be able to get it to count to 40.