The Role of Order of Operations
One of the biggest reasons people get these problems wrong is a misunderstanding—or forgetting—of the order of operations.
Many people remember a version of it from school:
- Multiply and divide
- Add and subtract
But memory fades, and intuition takes over.
When numbers are presented in a linear format, the brain tends to calculate left to right, even when that’s incorrect. This habit is strong because in everyday life, left-to-right reasoning often works well enough.
Math, however, does not reward “good enough.”
Why Confidence Makes It Worse
One of the most interesting aspects of these problems is how confident people feel about their answers.
You’ll often see:
- Strong opinions
- Arguments
- Insistence that others are “overthinking it”
This confidence comes from familiarity. The problem looks like something we’ve seen before, so we trust our instincts.
Ironically, the more confident someone feels, the less likely they are to double-check their work.
In psychology, this is closely related to the Dunning-Kruger effect, where people overestimate their understanding of something simple because they don’t realize what they’re missing.
- Ability to override intuition
In other words, they test thinking habits.
That’s why people who are excellent at complex math can still make mistakes on simple-looking problems.
