Trying to find an isekai about math

[Jellyman_i_guess]

So the mc is isekai'd into a shabby shack wich is actually the FL's hidden base and meets with the FL and then helps with the FL's problem, and because she's a princess, it's something like a kingdom's military problem of sorts that req. His help, so he helps. I don't remember much after that.
I think he had a gun but I'm unsure
The MC also had some flashbacks about his grandpa and some graph in the image of boobs but as a graph (just google boob graph) while he talks about stuff and that's about all i can remember.

 

[recry01]

maybe this one.

https://mangadex.org/title/89ed3ec2...d-coins-in-the-different-world-for-my-old-age

 

[VladTheImpaler]

Dang, I know exactly what you are talking about but I can't find it.
😓

 

[konpyuutasan]

"Suuji de Sukuu! Jyakushou Kokka"​

It's not strictly a flashback with the boob-graph, it's the opening panels. Naoki is trying to find a way to make math more popular

​

 

[Jellyman_i_guess]

maybe this one.

https://mangadex.org/title/89ed3ec2...d-coins-in-the-different-world-for-my-old-age

Nope, but thanks man

 

[Jellyman_i_guess]

"Suuji de Sukuu! Jyakushou Kokka"​

It's not strictly a flashback with the boob-graph, it's the opening panels. Naoki is trying to find a way to make math more popular

​

It was this one!!! Thanks! Looks like i remembered wrong then