So, am I too dirty or this chapter has a lot of hints for MC's deadly number ?
From what I can see, the ruler is often about 20cm or 30cm.
So if it's a 20cm ruler then MC's deadly number is about 15-18cm long.
If it's a 30cm ruler then his number is about 2x cm long ( not likely )
Also the 15 => 0 cm film too, is that a hint too ?
Conclusion for the last chapter question: MC's deadly number is about 15 - 18 cm long and with a thickness about the same or even bigger than a regular ruler. Yeah, dude is packing.
No, what am I doing

? Surely I am not the only one trying to figure out this right ? The hints are all over the place for me to just ignore it.