Sum column of numbers with specific criteria

[gray-ish]

Hello!

I have a question about summing all numbers in a column.

One column contains the numbers I want to sum. A second column contains a second dimension, such as Product A, Product B, and Product C (simply A, B, and C). How do I sum only the numbers that associated with Product A? I do not want to sort the Product column and manually sum the segments.

I've tried a combination of sum, sumif, if, etc, but the total is always off.


Thanks for taking the time to read this and dealing with my re-post. I appreciate your patience.

Best,
g