2 questions about my answer for an interview question

Hi,

Below is my answer for an interview question:
Tell me a time when you explain something.

Question1:
Should I change the “told” (the red one) to other word?

Question2:
Should write the blue text in past tense or present tense?

Answer for the interview question:
One day, my teammate asked me how to calculate the expected cost.

I used the most easy to understand way for him to explain.

He studied Economics, so he is good with theory and application, but not good with mathematics.

Therefore, I told me the steps for calculating expected cost, rather than showing him complex calculation.

Our Finance team will calculate the expected cost.

First of all, they will calculate the expected cost of raw materials.

Then, they input those items into our cost model.

The output of the cost model is the expected cost in each region.

Finally, they add the expected cost in each region together.

The result is the expected cost of our company.

He told me that he understand my explanation.

He also said I was able explain complex idea in an easy to understand way.

Thanks