This app was mentioned in 3 comments, with an average of 2.67 upvotes
There is the free WWG Health Tracking app, if you have a phone around (e.g., from the Google.Play store: https://play.google.com/store/apps/details?id=com.whitewizardgames.lifetracker ) or there are a whole bunch of free, non-branded apps that do the same thing you can check out.
Otherwise, poker chips would also work; they might not be numbered, but you're only keeping track of two- or three- denominations, so it's not too hard (or, you just count with 1s and 5s, further reducing the memory work).
If you have a smart phone or tablet, you could get the free app from White Wizard: Epic ScoreKeeper.
iOS: https://itunes.apple.com/us/app/epic-scorekeeper/id1069393659?mt=8
Android: https://play.google.com/store/apps/details?id=com.whitewizardgames.lifetracker&hl=en
My link for it still works: https://play.google.com/store/apps/details?id=com.whitewizardgames.lifetracker