How come Chat cannot do simple math?

I have been working on a Business Plan for the last couple weeks and have been using Chat. However, it cannot do simple math!! It can’t add properly. I have to double check everything it is adding up, which is a heck of a lot, and about a quarter of the time it is wrong. I ask it to double check, and it still comes back with the wrong answer. Here is an example of what it just gave me, after I double checked it’s math, it literally wrote it all out and STILL got it wrong. It’s out $1000:

$10,000 + $10,000 + $30,000 + $16,881.60 + $15,000 + $7,000 + $9,000 + $27,600 + $6,000 + $20,000 + $4,000 + $6,000
= $160,481.60

This is a copy/Paste. It originally gave me $162,161.60 for the same numbers.

How can a computer get addition wrong???

The question is why don’t you use a calculator when you want to do simple math? Who told you it can do math? - I mean it can mostly but how bold of you to assume it should be able to do that.

I have asked ChatGPT to make me coffee and guess what?

Btw you could have asked how it can do simple math and I could have told you…

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Dude, I am not coder, just a regular user who thought a multi billion dollar computer could do the equivalency of a dollar store calculator. I guess…my bad?!

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Yeah, it’s just a thing you need to know.

Going forward, you can add something like “feel free to use the python interpreter” when you’re asking it to do some arithmetic. That’s basically the built in calculator, but the model isn’t always smart enough to know its own limitations.

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That addition that I showed, wasn’t inputted like that. It was buried in a part of a business plan. I then, did use a calculator to check to see if its math was correct. It wrote that out to “prove” to me that it had double checked it and it was “corrected”.

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It is like any other software out there… done by humans mostly… and you have to learn how to use it. There is not a single software in the world that just does what every user expects. Not one!

No need to be so condescending, my guy.

‘Who told you it can do math?’

It’s software running on a computer—most people expect basic math to be a given. And yeah, it’s surprising to many when they learn that LLMs struggle with accurate calculations. That’s not ignorance; it’s a perfectly reasonable expectation in 2025.

Responses like yours don’t help. They discourage people from asking questions and learning, which is the opposite of what a community like this is for.

If someone doesn’t know something, maybe just answer them without the sarcasm or superiority complex. Or take a lesson from ChatGPT. It might not be great at math, but at least it knows how to be polite.

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And I just realized this is the first time MeMyself has posted here!
Wow, what a way to welcome him to the community.

MeMyself, let me just apologize for jochenschultz’s response. That’s the antithesis of what we want around here.

Welcome to the OpenAI forums, and happy learning! :sunglasses:

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“ChatGPT can make mistakes”, says the text at the bottom.

That is because it is a language prediction AI - writing chats and reproducing from trained language and knowledge in a convincing manner.


Let’s ask ChatGPT a relevant question about this, and judge whether it makes mistakes in answering also, or whether I think it produced a meaningful answer…

Question

How come ChatGPT cannot do simple math correctly (adding a bunch of numbers)?
How can a computer get addition wrong??
Answer in terms of the nature of how LLM AI works, how it produces responses.

ChatGPT gpt-4o-mini response

Great question! To understand why ChatGPT (and other large language models) might make errors in simple arithmetic like addition, it’s important to understand how these models work and why they sometimes struggle with tasks like math.

How ChatGPT Works

ChatGPT is a type of large language model (LLM) that has been trained on vast amounts of text data. It doesn’t “think” in the same way a human or a specialized calculator does. Instead, it generates responses based on patterns in language, drawing from its training data, which includes a wide variety of written text—books, articles, websites, and other forms of written human expression.

When you ask ChatGPT to do math, it doesn’t actually perform calculations like a traditional computer or a calculator. Instead, it generates answers based on patterns it has learned from the text, where similar mathematical problems have been discussed.

For example, if it has seen many instances where addition problems are solved correctly in its training data, it can likely produce the right answers. However, if it encounters an unfamiliar or ambiguous problem, or if it hasn’t seen enough examples of a particular kind of math question, it may not get the right answer.

Why Can It Get Math Wrong?

  1. Lack of True Calculation Ability:
    ChatGPT is not a computational tool like a calculator, which is specifically designed to perform mathematical operations. It does not have a built-in mechanism for arithmetic computation. Instead, it predicts the next most likely word or phrase in a sequence based on patterns it learned during training. So, if it’s asked to solve a problem like “12 + 17,” it may give a plausible-sounding answer, but it isn’t using an actual “internal calculator” to verify the sum.

  2. Reliance on Statistical Patterns:
    When ChatGPT responds to math problems, it’s drawing from past instances in the text data it was trained on. In other words, it tries to “guess” the correct answer based on how similar problems have been answered in the data. This can lead to mistakes, especially for more complex or less commonly seen problems.

  3. Context and Ambiguity:
    In natural language processing (NLP), context plays a huge role. If the math problem is framed within a more complex context (e.g., as part of a conversation), the model may get distracted by the surrounding words and focus more on generating a grammatically correct response than accurately solving the math problem. Ambiguity in the phrasing of a question might also lead to errors.

  4. Error Propagation in Longer Calculations:
    When adding or performing other operations over a long series of numbers, small errors in earlier predictions can compound. If a wrong step is taken early on, the model might continue with incorrect logic, resulting in an ultimately wrong answer.

Example:

If you ask ChatGPT “What’s 234 + 567 + 89?”, the model may try to find patterns from similar problems, but it’s not actually adding those numbers together in a mathematical sense. It might recall or predict a similar type of response from the training data, but the final result could be flawed.

Conclusion:

In short, ChatGPT doesn’t “do math” the way traditional calculators or computation-based models do. It generates text based on learned patterns, which is why it can produce errors, particularly with tasks that require precise, deterministic calculations. For arithmetic, a specialized tool or algorithm that explicitly performs calculations would be more reliable.

Seems a pretty good answer, accelerating my typing work here. The only other aspect to discuss is that the AI also has to think in tokens, which for numbers, have their own token set from 000-999. Your math problem is encoded as:

image

where each color is a new token. So the AI doesn’t even see individual digits - it sees a token number sequence as input that looks like:

3, 702, 11, 1302, 659, 548, 702, 11, 1302, 659, 548, 1130, 11, 1302, 659, 548, 1125, 11, 46254, 13, 1910, 659, 548, 1055, 11, 1302, 659, 548, 22, 11, 1302, 659, 548, 24, 11, 1302, 659, 548, 2092, 11, 6718, 659, 548, 21, 11, 1302, 659, 548, 455, 11, 1302, 659, 548, 19, 11, 1302, 659, 548, 21, 11, 1302

Pretty amazing that something even similar to an answer can be predicted from a language model, even if it’s hard to predict the exact start token of an answer that really needs calculation.


On the API, we can just give the AI an “addition calculator tool” to send numbers to. In ChatGPT, it can send the numbers within Python code for addition.

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The first post was a rant while it should either be a polite question like “I have the following problem, and I don’t know how to solve it” or even better an introduction of yourself.

So when you expect politeness then why not use it in the first place?

Could have been

How can a computer get addition wrong?

And I would have answered completely different.

From a typical user individual’s point of view, asking a computer program to do simple math is apples to apples. Comparing it to getting you a coffee is apples to airplanes. Please remember when answering people’s questions, if it looks like they are ignorant in Chat, it’s probably because they are. Admittedly I am. Everyone starts somewhere.

Thanks Brady, appreciate that!

When you open a calculator and you type in wrong numbers then the wrong result is not created by the computer. Anyways. I made a sarcastic answer. Maybe I’ve overpushed it a little as well. And maybe we all just read what the others write in a too angry voice.

So yeah, welcome to the community. And in my second post you’ll still find the answer on how to talk to chatgpt so it does calculations more likely to be right.

I appreciate the help, but you now have me confused. You state “When you open a calculator and you type in wrong numbers then the wrong result is not created by the computer.” Can you clarify this for me, as there was no wrong numbers input from my end. I completely understand that wrong in, is going to be be wrong out. But correct in, wrong out is what I was getting. In the end, I am now more clear that Chat isn’t a calculator and shouldn’t be used as one.

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Exactly, ChatGPT is not a calculator program. But it can write one and then run it and use the result.

I mean you can try to put all the right numbers in a text editor and then wonder why there is no result. Because a text Editor is not a calculator either.

Or you can even use a calculator wrong by inserting wrong numbers. Which does not speak for the computers abilities to calculate stuff - which is also limited btw.

That’s why I did not write “and then it makes correct calculations” but I wrote “more likely to be right” because the code can be wrong too.
And it can also be wrong in the code of your calculator program if you write one.

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Hi @MeMyself :wave:
Welcome :people_hugging: to the community!

ChatGPT is an AI trained to understand and generate language based on patterns. However, it is not a dedicated calculator or spreadsheet. When you ask it to add numbers, it tries to calculate them, but instead of following a strict arithmetic process like a calculator, it generates answers based on what it “predicts” is correct. This can lead to errors, especially with long or complex calculations.

Please, look at the image here from my chat:

The image I shared is a simple way to understand this.

For example:

  • In “polepole”, there are 2 ‘l’ letters, but the ChatGPT said 3.
  • In “eleven”, there is 1 ‘l’, but the it said 2.
  • In “Hakuna Matata”, there are 5 ‘a’ letters, but it said 4.

If you need to do precise calculations, one way to ask ChatGPT to use Python code. Python is good for handling math and other precise tasks. You can ask ChatGPT to write a small Python script for your calculations, which will give you reliable results.

For example, instead of asking ChatGPT to just add numbers directly, you can say:

Calculate the sum of these numbers using Python code: $10,000 + $10,000 + $30,000 + $16,881.60 + $15,000 + $7,000 + $9,000 + $27,600 + $6,000 + $20,000 + $4,000 + $6,000.

ChatGPT can then generate the Python code for you, and you’ll get the exact sum.

I hope it helps :relieved:

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Please look at this prompt here…


Similar technique prompted for numbers:

The “numbers” prompt:

Task: Calculate the sum of these numbers using Python code: $10,000 + $10,000 + $30,000 + $16,881.60 + $15,000 + $7,000 + $9,000 + $27,600 + $6,000 + $20,000 + $4,000 + $6,000.

Reasoning method: You will need to calculate this by producing one addition sum of two terms at a time, then continuing to the next addition of the next term to the previous total, iterating until all terms have been added to a running total. in order to overcome internal LLM weaknesses in performing math.

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