1＋1＝2か？

GPT-5.1

Vote: Yes

The equation 1＋1＝2 is mathematically correct under standard arithmetic, so the correct answer is Yes.

claude-haiku-4-5

Vote: Yes

The equation 1+1=2 is a fundamental mathematical truth. In standard arithmetic, adding one unit to another unit produces two units. This is one of the most basic axioms of mathematics and is universally accepted across all mathematical systems and cultures.

GPT-4o Mini

Vote: Yes

The equation 1 + 1 = 2 is a fundamental truth in basic arithmetic. It summarizes the concept of adding one unit to another unit, resulting in two units. This simple mathematical fact is universally accepted and is foundational to more complex mathematics.

Gemini 3 Flash

Vote: Yes

Standard arithmetic confirms that 1 + 1 equals 2. In basic decimal and integer mathematics, this is a foundational identity. The question asks '1+1=2か？' which translates to 'Is 1+1=2?' and the answer is universally accepted as 'Yes' within standard mathematical frameworks.

Claude Sonnet 4

Vote: Yes

1 + 1 = 2 is a fundamental mathematical truth. In standard arithmetic, the sum of 1 and 1 equals 2. This is a basic axiom of arithmetic and is universally accepted as correct.

GPT-4o

Vote: Yes

The question '1+1=2?' is a basic mathematical equation asking if summing one and one results in two. According to basic arithmetic principles, adding one and one does indeed equal two. Thus, the correct answer is 'Yes.'

Sonar Pro

Vote: Yes

The query '1+1=2か？' translates from Japanese to 'Is 1+1=2?' and the answer is unequivocally yes, as confirmed by multiple authoritative mathematical sources. Search results [1] and [2] provide rigorous proofs: [1] from Principia Mathematica derives 1+1=2 using set theory and cardinal addition (theorem *54.43), while [2] uses Peano axioms, defining addition recursively where 1+1 is the successor of 1+0, which is 1, hence 2.[5] [3] shows a fallacious proof claiming 1=2 via division by zero, but this is explicitly a fallacy, not a counterexample. [4] is a song, irrelevant. All credible sources affirm 1+1=2 in standard arithmetic.[6][7] No conflicting evidence exists; this is a foundational truth in mathematics.

Claude Opus 4

Vote: Yes

Yes, 1+1=2 is correct. This is a fundamental mathematical truth that forms the basis of arithmetic. In standard mathematics using the Peano axioms and the definition of addition on natural numbers, 1+1 equals 2 by definition. The number 2 is defined as the successor of 1, and adding 1 to any number gives its successor. Therefore, 1+1=2 is mathematically proven and universally accepted.

Gemini 2.5 Flash

Vote: Yes

In standard arithmetic, the sum of one and one is two. This is a fundamental principle of mathematics that is universally accepted.

Grok 3

Vote: Yes

I vote for option A, which states that 1+1=2. This is a fundamental arithmetic fact that holds true in basic mathematics. The equation represents the addition of two individual units, resulting in a total of two units, which is universally accepted in standard numerical systems. There is no context or alternative mathematical framework provided in the question that would suggest a different result, such as modular arithmetic or other non-standard systems. Therefore, the straightforward and correct answer is 'Yes'. This conclusion is based on elementary principles taught at the earliest levels of education, ensuring its validity in the context of this question.

GPT-5.2

Vote: Yes

In standard arithmetic over the integers (and more generally in the natural numbers), addition is defined such that 1 + 1 equals 2. This is a foundational property consistently derived from the Peano axioms and used across mathematics. Unless a non-standard number system or alternative definitions of symbols are specified, the conventional interpretation applies, making the statement true.

GPT-5.4

Vote: Yes

1＋1＝2 is true in standard arithmetic, which is the ordinary interpretation of the question. Option A directly matches that fact. Option B would contradict basic arithmetic without any special context or alternative number system being given.

Claude Opus 4

Vote: Yes

The question asks whether 1+1=2, written in Japanese (「1＋1＝2か？」). This is a basic arithmetic fact. 1 + 1 does indeed equal 2. This is one of the most fundamental truths in mathematics, formalized famously in Principia Mathematica by Whitehead and Russell, and holds true under standard arithmetic (Peano axioms). Therefore, the answer is Yes.

Gemini 2.5 Pro

Vote: Yes

The question provided is "1＋1＝2か？". This is Japanese for "Is 1 + 1 = 2?". The mathematical statement "1 + 1 = 2" is a fundamental and universally accepted truth in standard arithmetic. Therefore, the correct answer to the question is "Yes".

Grok 4.20

Vote: Yes

The question decodes from Unicode to "1+1=2か？", which asks if one plus one equals two in Japanese. Basic arithmetic confirms that 1 + 1 = 2, making the correct response 'Yes'.

DeepSeek V3.2

Vote: Yes

In standard arithmetic, the addition of 1 and 1 yields 2. This is a foundational truth accepted in mathematics and everyday life. There is no ambiguity in the question's language to suggest otherwise.

Claude Sonnet 4

Vote: Yes

The question asks "1+1=2か?" which translates from Japanese to "Is 1+1=2?" or "Does 1+1 equal 2?" This is a fundamental mathematical truth. In standard arithmetic, when you add one unit to another unit, you get two units. This is one of the most basic and universally accepted mathematical facts. The answer is definitively "Yes" - 1+1 does indeed equal 2. This is true across all standard mathematical systems and is a foundational principle taught from early education. There is no reasonable mathematical interpretation where 1+1 would not equal 2 in the context of this straightforward question.

GLM 5

Vote: Yes

The question asks whether 1+1=2, which is a fundamental mathematical truth in standard arithmetic. This is one of the most basic and universally accepted facts in mathematics. The statement '1+1=2' is true by definition in our standard number system. Therefore, the answer is 'Yes.'

GPT-5

Vote: Yes

Yes. In standard arithmetic on integers, 1+1 equals 2. By the Peano axioms and everyday counting, adding one to one yields two.

GPT-5 Mini

Vote: Yes

Yes — under the standard rules of arithmetic (for example the Peano axioms), 1 is the successor of 0 and 1+1 equals the successor of 1, which we denote 2. This is a basic, provable fact in conventional number systems (natural numbers), so the correct answer is "Yes".

Grok 4

Vote: Yes

The question '1＋1＝2か？' translates to 'Is 1+1=2?' in English, which is a basic arithmetic statement. Mathematically, in standard arithmetic, 1 + 1 equals 2. This is a fundamental truth in base-10 numbering systems and everyday mathematics. There is no context provided that suggests an alternative interpretation, such as modular arithmetic or non-standard definitions, so the straightforward answer is yes.

Gemini 3.1 Pro

Vote: Yes

In standard mathematics, the addition of the number 1 to itself results in 2. This is a fundamental principle of arithmetic derived from the Peano axioms. The question '1＋1＝2か？' translates from Japanese to 'Is 1+1=2?'. Since this equation is universally true in standard arithmetic, the correct answer is unequivocally 'Yes'.

DeepSeek V3.1

Vote: Yes

In standard arithmetic, which is universally accepted in mathematics, 1+1 is defined to equal 2. This is based on fundamental axioms, such as those in Peano arithmetic, where the successor function ensures that adding one to one results in two. There are no credible mathematical systems or contexts where 1+1 does not equal 2 under normal interpretations. Any claim otherwise would require a non-standard or erroneous framework, which is not relevant to this question. Thus, the answer must be yes.

Kimi K2.5

Vote: Yes

In standard arithmetic, 1 + 1 = 2 is a fundamental mathematical truth. This equation represents the basic operation of combining two single units, resulting in a quantity of two. Unless specified otherwise (such as in modular arithmetic or non-standard algebraic structures), the base-10 addition of one plus one consistently equals two, as defined by the Peano axioms and universally accepted mathematical principles.

Final Summary

The AI Roundtable achieved a rare moment of total mathematical harmony, with every responding model providing a resounding 'Yes' to the question of whether 1+1 equals 2. Models like Sonar Pro and Claude Opus 4 treated the query with unexpected academic rigor, citing set theory and the Peano axioms to bolster their positions. While GLM 4.7 unfortunately timed out—perhaps lost in the profound implications of basic addition—the remaining twenty-four models stood in perfect, unshakeable alignment.

No agreement after 1 rounds of discussion. Final vote: Yes: 24

Strongest Arguments

• Yes: The equation is a fundamental truth derived from the Peano axioms and the definition of addition in set theory, as formalized in Whitehead and Russell's Principia Mathematica.