How to step into a formula

One strategy to debug a complex formula is to find out which step has gone wrong using “Step Into” function on the formula auditing tool bar.

1. We have an array formula that does the sumproduct functionality.

2. Display a Formula Auditing toolbar. The right-most button is what you need to step into a formula.

3. The underlined portion is what is going to be calculated in the next step. For this example, we expect Excel to multiply corresponding numbers in C2:C5 and D2:D5.

4. Evaluate once, the result from previous step is show. The next step is to do the Sum.

5. Evaluate one more time, we get the final answer.