“Because of these modern math rules, the official correct answer today is 16.”

 

There is no universal modern mathematical rule that says implied multiplication must always be treated exactly the same way in every context. Different textbooks, calculators, and software have historically interpreted expressions like 8 ÷ 2(2 + 2) differently because the notation itself is ambiguous.

A more accurate explanation would be:

• Evaluate the parentheses first:

  $$8÷2(2+2)=8÷2(4)$$

• The expression is now:

  $$8÷2\times 4$$

• If multiplication and division are treated with equal precedence and evaluated left to right (the convention used in many modern textbooks and programming languages), the result is:

  $$8÷2=4,4\times 4=16.$$

• If implied multiplication $2(4)$ is interpreted as binding more tightly than division (a convention used in some older texts and by some calculators), the expression becomes:

  $$8÷(2\times 4)=8÷8=1.$$

The real mathematical lessonThe real mathematical lesson

Professional mathematicians generally avoid writing expressions like

$$8÷2(2+2)$$

because the notation is ambiguous. Instead, they would write either

• $(8÷2)(2+2)$, which clearly equals 16, or
• $8÷[2(2+2)]$, which clearly equals 1.

Verdict

The article is correct that:

• These viral puzzles are designed to generate arguments.
• The notation is intentionally ambiguous.
• Clear use of parentheses eliminates the confusion.

However, it is not correct to state that 16 is the one official correct answer today. The mathematically correct conclusion is that the expression is ambiguous as written, and its value depends on the convention used to interpret the notation. In formal mathematics, the preferred solution is simply to rewrite the expression so there is only one possible interpretation.