#math theory

1) The first girl that Chris brings at home, eating pizza and playing videogames is Penny, a blonde girl that he met at math class (as Eddie told to Buck) and Eddie say that he doesn’t get if it was a date because it seems to him that they were just hanging out as two male friends do (👀👀). Even though from the scene we know Christopher and Penny are smiling so they both are enjoying this date. Even though Eddie can’t see it because he was behind them and watching them afar

Now, It's pretty obvious who they are referring to because videogames and pizza is what Buck, Eddie and Christopher did from the past 6 years. Penny is blonde as Buck and him and Eddie smiled everyday when they are with each other because they enjoy their time with each other

The math class also is a methaphor because in the past seasons we saw that neither Eddie and Buck knows anything about math until Buck died and when he came back he knew all the answears and he was a jenious at math. That brought them to their first poker date night togheter as Chris and Penny dated because they met in math class. Even though neither of them knew it was a date

Eddie watching Chris from afar it can be also a methaphor of the fact that now he can’t see what he have with Buck because he doesn’t think that what they do is romantic coded or anything but then Buck line came and it's very important because Buck is the first one who are saying that there is just ONE CASE where there's underlying sexual tension and Eddie face to that was speechless. Almost as he got what Buck said but he doesn’t want to think about it. So what Eddie did? He just change the subject

Because if we think about it, in episode 5, Eddie didn’t think Buck and Tommy was interested in each other in a romantic way. Also, Eddie didn’t think Tommy was gay in the first place and it freak Eddie out a bit but then he just proceed to support his best friend because nothing will ever change his bond with Buck. As he tried to change the topic and talking about something else. But then at the bachelor party Eddie couldn’t hide his feelings and from his expression is pretty obvious is jealous of Tommy

But what Eddie did in next episode? Instead of understand why he was a little mean to Tommy he put himself in an emotional cheating relantionship with a copy of his dead wife (💀💀). Again, he's trying not to think about it and putting that feeling away. Changing the subject

2) The second girl Chris was talking to, she was a black hair girl who we don't even know her name (👀👀). As we don't know Marisol last name. And the first thing we see about her is her jealous towards Penny because Chris was two timing her. As now Eddie is doing it to Marisol with Kim. And if Tim wasn’t jocking with the Vertigo post, we know Marisol (the nun) will break Eddie illusion to bring back Shanon on his life and of course they will break up in the end (😍🥳)

3) Buck talked with Christopher of why he was seeing more than one girl and how it was wrong for his sake. Christopher answer that he doesn’t care about them because he knows they will leave him in the end as his mom did. Eddie heard them and later he give his son the Shannon letter and with that. It seems Christopher have his closure with his mom (We don't know it yet until the last two episodes airs)

Now, from Ryan interview we know Buck is going to meet Kim and I think if that's so. Then Buck would try to tell Eddie how it is wrong for his sake and his relantionship with the nun (lol) as he did for Christopher. But I think also, that as Christopher didn’t listen to him. Eddie won't listen to Buck either. Because Eddie is still missing Shannon in some ways and seeing her in Kim face made him again romanticed his marriage with her. When we know the memories he played weren’t happy ones but where we saw there were problem in their marriage. Problems in wich Shannon asked Eddie to divorce him before dying

I think the monsters use base-12. (I’m going to go ahead and explain base-12 since it’s not common knowledge, if you already know then you can skip the next paragraph!) Basically, base-12 (or duodecimal) is a numerical system in which twelve is the first double-digit number. Counting in duodecimal would look like this: 1, 2, 3, 4, 5, 6, 7, 8, 9, X, Ε, 10 With X being equal to ten, Ε equal to to eleven, and 10 equal to twelve. The values are still the same, but the characters used to represent them change. This is admittedly a pretty sucky explanation but if anyone is genuinely curious I can try to do better lol ANYWAY my friend initially brought this up; she immediately paused after getting this dialogue:

[Image Description: Two text boxes indicate Papyrus’s dialogue. The first reads “I’m just a dozen away...” and the second says “from a double digit follower count!”] If monsters are using duodecimal, this would make a lot more sense! Instead of having -2 followers like he would have in decimal (or 111 if you want to get SUPER nit-picky), he would just have... 0. I think this is probably the most convinving piece of evidence in our favor. Of course it could just be some fun dialogue Toby through in as a joke, but overanalysis is fun so. I’m not stopping there. Next I noticed the in-game year:

[Image Description: A screencap from the opening sequence. Pictured is a mountain, labelled Mt. Ebbot 201X] So, initially, I believed 201X was meant to indicate some year between 2010 and 2019, with X replacing the last number. BUT if you consider that X is a character marking the value of ten in duodecimal, the year becomes 3478 in decimal (aka base-10, the number system we use). Now if the year had only been mentioned in the opening sequence, it would be a lot easier to play off as an unknown, but it’s written on a calendar in Asgore’s house!

[Image Description: A screencap from inside Asgore’s house. Frisk is inspecting a bookshelf. The text reads “There’s an old calendar here from the end of 201X. A date is circled on it.”]

You can’t really make a calendar for a nondescript year (unless he’s got just... a nine year calendar?) so it would actually make more sense, in my opinion, for 201X to indicate an exact year in duodecimal than a range of years in decimal. Those are my really hard-hitters, but I also think it’s cool to think about WHY monsters would use duodecimal. The reason humans use base-10 is because we typically have 10 fingers. It would be easier for a person with 10 fingers, 10 ‘digits,’ to use a mathematical system based around the number 10. But as far as I can tell, monsters don’t have 10 fingers. Granted, this could be more related to art-style, but the coincidences are stacking up at this point, right? Look at these sprites:

[Image Description: Toriel’s death sprite. She’s holding one hand against her chest while the other rests on the floor.}

[Image Description: Mettaton’s first battle sprite. He holds a microphone in one hand. His other hand is outsretched.] I dug through a lot of sprites trying to count fingers, but these two stood out the most: They both appear to have 4 digits on each hand. If we are to assume that the monsters have been sealed underground for a while, it would make sense for them to eventually convert to a numerical system that fit them better, right? So they would probably want to choose a base divisible by the number of fingers they have on a hand. It just so happens that 12 is divisible by 4.  Sure, they could also use another base like 16, but Papyrus’s initial comment and the fact that X is used instead of A have me leaning towards 12.

TL;DR the monster’s numerical system revolves around the number 12 instead of 10.

So yea, this is me doing math about seasons and all of the Arrows’ ages and numerical information. This is good for evidence for other theories so I’ll probably link back to it in future posts, and feel free to use anything you find helpful in this theory.

Below we’re going to be finding the age gap between odin and his triplet sisters. Then we can use that, along with some other numbers, to see when in their lives their mother could’ve died. 

Odin is 18 years old (rounding up from panel #2160), and he say’s that’s 3 3/5 (or 3.6) in this panel. 

If 18 = 3.6, that means that 1 season = 5 years (or you could say .2 seasons = 1 year).

Magpie’s been gone for half a season (panel #2196). 1/2 seasons = 2.5 years. 

The triplets are 2 2/5 (2.4) seasons old. 2.4 seasons = 12 years. (panel #1198).

Since Magpie has been missing for 2.5 years, we can subtract that from 12 to get magpie as 9.5 years old when she went missing. (This is kinda off topic but I might use this in a Magpie theory some other time, or you guys can use it in your theories, idrk.)

So Odin is 6 years older than his sisters.

He was 2 seasons when the planet started dying. 2 seasons = 10 years. (panel #2178).

The portrait of himself that is the only painting he’s ever hated was taken during the age of Death, I’m assuming, based on the snow outside looking much like the depressed snow he shows us in the flashbacks. He looks around 10 years of age in the portrait, so I’ll be going with that number.

He also does not look happy to be there. Odin doesn’t show his negative emotions too much, but he definitely is not feeling anything positive as they painted this. With his mother being as important to him as I think she was, I find it safe to assume his mother had died recently in this portrait. 

Going off of these loose assumptions, Odin’s mother died when he was 10 and the triplets were 4. Scientists believe that children start forming solid memories around the age of four or later.

This means the probability of the twins remembering anything about their mother past a few fuzzy moments is really low. 

Then knowing to do math when his husband and kid where in his apartment...

Buck saying is the guy with the answers now because he know how to do math...

Eddie saying the same thing to him but knowing Buck shouldn't date Natalia for how he met her like Buck met his past girlfriends...

Buck thinking his answer is dating a woman he met like he did with other women in the past...

Buck mistarderstood the asaigment when it came to draw a heart...

In coclusion:

This post is less formal than my previous one, but I still need to express this prediction, as I believe there is a slim but nonzero chance that some symbolisms of Deltarune's proper nouns get revealed in Chapter 5. As such, I must show my hand in what I believe one of the most prominent symbols means. As such, I will talk about the Delta Rune.

In Undertale and in Deltarune, we hear about the legend of the Delta Rune. It is closely tied to the prophecies that hold the most significance to the stories' plot. However, in neither of these prophecies do we discover what said rune does. I think I found a convincing argument for it, that works for both games, whilst not interfering with the plot in a significant way.

The greek letter for delta, in its most common use in mathematics, is given the purpose of symbolizing that the following variable is a differential of two values, and as such a change in them.

(i.e. slope. The slope in a linear graph is given by how y changes with respect to x. As such, it is y2 - y1, or delta-y, over x2 - x1, or delta-x)

A rune, in the classical sense is a character from a Germanic alphabet, though in fiction it is traditionally used for inscriptions that help you cast spells (See: TVTropes page on Runic Magic).

Join those together, and you get an inscription placed by who-knows-whom that causes changes in... something.

Say you were to have a world with a predestined outcome, in which nobody's choices really matter, as they all converge to a set course of events. Say someone were to become aware of this fact, and were to try and do some discoveries in their fictional world (or a faustian bargain) that let you change the overall outcome of the world, free from this restriction. This discovery is of an object that, in the higher planes of existence, is depicted as a simple symbol, a simplification of a heart that leaves an imprint on the higher beings'... screens.

This such inscription on their screens causes change in the outcome of events, and as such is a Delta Rune.

Quod Erat... Dubitabilis.