Overview
- Three Argentine news sites published short mixed‑operation puzzles on Thursday and Friday, each giving the full PEMDAS solution and a final numeric answer.
- The puzzles and published results were (700 × 5 + 100) ÷ (6 × 1) = 600, 8 × 4 – 15 + 12 ÷ 4 – 19 = 1, and (25 × 4 - 20) ÷ (15 + 5) = 4, with step‑by‑step breakdowns that apply parentheses, multiplication/division left to right, then addition/subtraction left to right.
- All three pieces emphasize the order of operations as the main cause of common mistakes, warning that treating expressions strictly left‑to‑right under time pressure produces wrong answers.
- One outlet described its puzzle as viral and reported that “80%” of people fail to solve it, a claim presented without independent verification in the coverage.
- The articles frame these brain teasers as light cognitive training and cite existing neuroscience work such as Yaakov Stern’s research on cognitive reserve, but they do not report new scientific findings.