Starting at 100% I have 82 clients 2 of them didn't get a check up what percent does that leave us at?

82 total clients

2 did NOT get a checkup

(82 - 2) = 80 clients DID get a checkup

80/82 = 0.97561 = 97.561% of your clients have had their checkup.

Interestingly, that's the exact same percentage of your clients who have had lunch. Perhaps ... I'm not stating this as a fact, but it's a hunch ... just maybe the other two have not had their checkups yet because they are out getting lunch.