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View submission: Ask Anything Wednesday - Engineering, Mathematics, Computer Science
Humanity has evolved at least 4 different methods of counting on hands.
Ten fingers is the least useful. For one, it requires both hands and it's not that challenging to just remember. You also cannot count higher than 10 without getting complicated.
Base-5 is tally marks. I, II, III, IIII, ~~IIII~~. Let's you hold a pen in one hand. With two hands you can count to 25 by letting each finger on the second hand = 5, 10, 15, 20, 25 (or 10, 20, 30, 40, 50 if it is truly base-5).
Base-12 is your knuckles. Hold your left hand out, palm facing towards yourself. Use your thumb to tap each line on each finger: pinky 1, 2, 3; ring finger 4, 5, 6, etc. Let's you count to 12 while holding a pen. You can then use your other hand as the "10" increment. Means you can count to 144 with two hands, a number you cannot easily remember.
Base-16 is same as above but now use lines+finger tip. Counting to 256 with two hands? That lets you track bags of grain getting loaded on a wagon or count livestock crossing through a gate.
There's nothing here!