सिद्धान्तदर्पण (महामहोपाध्याय सामन्त चन्द्रशेखर सिंह - नग्न-नेत्र खगोल वेध एवं गणित महाकोश)

।१६) प्रहीनाः ।"
Wait, if it says "(१००)" or "(२००)":
Look at the first digit inside the parens:
It is: (१००) or (२००)?
Wait, look at the bottom of the digit:
It's just a curve that goes down, then a horizontal base? No, it's a '१'! Wait, why would it be १?
Wait, could it be (२००)? Look at the digit: compare it to '२' in '२१९' just to the left!
In '२१९':
The '२' has a round top, goes down to the bottom-left, makes a loop/knot, and extends a tail to the bottom-right.
The digit in question:
Does it have a loop/knot? NO! It does not have a loop at all.
Does it have a tail to the right? No, it just goes down.
Wait, but does it look like '१'?
Look at '१' in '२१९': it has a head and a straight vertical stem going straight down.
In this digit, it is a straight vertical stem with a hook at the top! It is 100% the digit '१'!
Wait, why is it १००?
Wait, look at the word before it:
Is it "द्विरथशत"?
Wait, could it be "द्विरदशत"? But why 10