I am researching the 12 hours of the ancient Egyptian night, and the spiritual journey through the duat. I have been able to find the ordinal numbers for the first hour through tenth hour online, tpj (𓁶𓊪𓏭) wnwt (tepi wenut) "first or head/lead hour" to mḥ-mḏw (𓎔𓎆) wnwt (meh medju wenut) "tenth hour". The mḥ (meh) means completing. I can not find the word for eleventh or twelfth. The numeric system goes straight from ten to twenty. There are ways to write 11th (𓎔𓎆𓏺) and twelfth (𓎔𓎆𓏻) numerically, but I can't find the word to express it, or the pronunciation. I used Bibalex.org and Wiktionary to gather this information. Any help with finding these words would be greatly appreciated.
It's possible there wasn't one.
The only reason English has words for 11 and 12 that aren't compound words is likely because we have vestiges of the Babylonian base 12/60 number system in our culture still in our time units (2 12 hour periods in a day1).
The ancient Egyptians had their own numbering system, which every source I've been able to dig up insists is base ten. If that's how they thought about numbers, it seems likely that any words they had for numbers past 9 would be compound words (unless all but one of their digits were zero). Looking around the net, I found a mnemonic glyph for 7, but that's the highest I found. This site claims they didn't even have a word for "nine".
There wasn't a symbol for every number, so multiples of values were expressed by repeating a symbol as much as it was needed to get to the total the Ancient Egyptians required.
For example, the Egyptians didn't have a symbol for the number nine. In this situation, if they wanted to write down that number, they wrote the number one symbol nine times.
If they didn't even bother with a "nine", and their number system didn't even have digits higher than that, it seems highly unlikely that they had unique words for "eleven" or "twelve".
The numbers glyph combos you included for 11 and 12, well they are very difficult to see in my browser, but according to this handy-dandy Unicode interpreter I pasted them into, the first is Hieroglyphic (Gardiners) V022 V020 Z015, and the second V022 V020 Z015A. Those are in fact the Hieroglyphic glyphs for 10's digit 1, and 10's digit 2 respectively, with a "whip" on the front. See the attached table:
The whip is apparently often used in the context of taking measurements (arms or cubits). So to my barely-educated eye, it looks to me a lot like what you've found there is the Hieroglyphic representation of "11 cubits" and "12 cubits".
1 - To be fair, it appears that the Egyptians also had 12 months in a year (or rather 3 seasons with 4 months each), and 12 hours in a day on their sundials. So they weren't Napoleonic about base 10. The former of course is a fairly hard limit if you want to try to use lunar cycles for "months"
Not sure this will help you but perhaps if you can interpret the hierogliphs in the Book of the Am-Tuat by Budge you might get an idea. From looking at his (Budge) Egyptian Hieroglyphic Dictionary I see no entries for eleven or twelve; perhaps they used 'ten and 1', 'ten and 2' syntax?