Subtracting from values from Sheet A in Sheet B

I'm using Excel 2010 and I can't get an upgrade at this time, so answers must be 2010 friendly

Volunteers earn $10 for each hour they volunteer to use toward services at our organization. I have a list of all the volunteers and hours worked in one worksheet. In a different sheet, I need to take their total hours worked from sheet A and deduct from that when they cash in their hours for services, and then get show the balance of credits for that volunteer in sheet B. What is the best way to do this?

I've tried a few different things including trying to work off a pivot table, and consolidating data, but I couldn't get either to do what I hoped it would. I'm open to suggestions of other methods! Thanks!

View attachment Volunteer and Community Service Hours.xlsx

Try this

Well that def works! Now I just need to figure out how you did it! THANK YOU! I'll take a closer look at the details this weekend!

I'm off next week, but I will try and pop in if you have any follow-up questions.