Proving 7 x 13 = 28 (Flat Earth Pseudoscience)
In these days when people proudly go on YouTube to proclaim their belief that the Earth is flat; it is important to remember why methods such as order of operations in math or the scientific method are important.
Last year a post by @upvotenev claimed a calculator was wrong that 2 + 2 x 2 = 6 and that it should be equal to 8. I explained in a comment to the post about how the calculator was performing order of operations. This is a mathematical convention that helps everyone be one the same page and prevent confusion such as whether an equation's solution is six or eight. Likewise the scientific method helps establish a system by which, when properly done, allows anybody to check and evaluate someone else's experiment.
Much like the above Abbott and Costello comedy routine some misguided people "prove" the Earth is flat using examples that ignore scale or just flat out misrepresent what science states. Unfortunately these simplified borderline-pseudoscience "proofs" of a flat Earth could look convincing to someone without the critical thinking skills to wonder why the person "proving" a flat Earth is holding a model airplane scaled larger than the continent of North America over a Fisher-Price Laugh & Learn Greetings Globe. Besides the reason that the homes of flat Earth supporters tend to be littered with nursery toys but strangely no toddlers.
Full Disclosure: Selling out to Fisher-Price. NASA and the United Nations didn't offer enough for me to troll the flat Earthers.