Guides
Background on the conventions the tools rely on — how an Arabic name is assembled, what an English place-name suffix records, why counting syllables is harder than it sounds. These are the explanations, written out properly.
Guide Understanding APR vs APY: the complete guide APR and APY are often confused. This guide explains the difference, the math behind each, and when each rate applies so you can compare loans, savings, and investments with confidence. Guide How to read a nutrition label: calories, fat, sugar, sodium Decoding the numbers on food packaging so you can compare products, understand serving sizes, and make informed choices without guessing. Guide The paving slab mistake: why calculators get it wrong How to avoid the offcut error when calculating paving slabs, and the simple rule to order the right quantity first time. Guide Password security: how long does it take to crack your passwords? How long it actually takes to crack a password, what makes a password strong or weak, and practical steps you can take today to protect your accounts. Guide BMI, BMR, and TDEE: what these body metrics really mean Demystifying the three key body metrics — Body Mass Index, Basal Metabolic Rate, and Total Daily Energy Expenditure — how they're calculated, and why they matter for your health goals. Guide What Google actually uses from your page's meta tags Some meta tags directly affect search results. Others do nothing for Google despite being widely believed to matter. Here is which is which. Guide Permutations and combinations: the one question that tells them apart Both count ways of choosing from a group. The whole difference comes down to one question: does the order you pick things in actually matter? Guide Why some files shrink a lot when zipped, and others barely shrink at all Zipping a text file can shrink it 80% or more. Zipping a JPEG or MP4 barely changes the size. The reason is the same for both — and it is no flaw. Guide Why a browser can't process a video faster than it plays Desktop software can re-encode a video in a fraction of its length. A browser tool usually can't — and it's a real limit, not a slow website. Guide Why some PDFs let you select text and others don't A PDF that looks like a document can be a photograph of one instead — and a photograph has no text in it, however readable it looks to you. Guide Why your keyboard sometimes drops a key when you press several at once Press three keys at once on the wrong keyboard and a fourth key can silently appear, or a real one can vanish. Both come from how it is wired. Guide How to pick the right chart for your data, not just a pretty one A pie chart and a bar chart can show the same data — and one of them is usually wrong for it. The right chart depends on the question, not on looks. Guide Why "random" on a computer usually isn't, and when that matters Most software random numbers come from a formula, not chance — deterministic and predictable if you know the start. Fine for games, risky for passwords. Guide Why an email or phone number extractor sometimes misses one, or catches too many There's no single definition of an email, phone number or URL — so any extractor enforces one reasonable set of rules among several possible ones. Guide What a JWT actually is, and why decoding one isn't the same as trusting it A JWT is three base64url sections stuck together with dots. Reading it needs no secret at all — which is why decoding one proves nothing about it. Guide Why pet names follow completely different rules than human names Pet-naming registries show clear patterns that don't apply to human names — shorter names, hard consonants, and a pull toward pop culture. Guide Why fantasy race names sound the way they do Elf names flow, dwarf names clunk, demon names hiss. That's not taste — it comes from sound-symbolism patterns fantasy writers have used for a century. Guide What size are Twitch and Discord emotes, really The exact pixel sizes for Twitch and Discord emotes - including the one number almost every guide gets wrong. Verified against the platforms themselves. Guide Which cup? US, metric and imperial cups are not the same A cup is not one measure. US customary, US legal, metric and imperial cups differ by nearly 20%. The exact figures and why a recipe can fail on it. Guide How an Arabic name is put together Ism, nasab, kunya, laqab and nisba: the five parts of a classical Arabic name, what each records, and why ignoring the structure produces nonsense. Guide What an Australian tax invoice must legally include The exact details the ATO requires on a tax invoice, the rule that changes over $1,000, and the one thing you must not do if you are not registered for GST. Guide What English place-name endings actually record -ton, -by, -thorpe, -chester, -combe: which language each ending comes from, what it originally meant, and why the endings cluster geographically. Guide GST is one eleventh of a GST-inclusive price, not ten percent The commonest arithmetic mistake on Australian invoices: taking 10% of a GST-inclusive total. The GST is one eleventh of it. Here is why, with the numbers. Guide Where medieval surnames came from The four sources of English surnames — occupation, location, patronymic and nickname — how they became hereditary, and why some are far commoner than others. Guide Why a UK DD is not a US DD: bra cup letters explained A cup letter is shorthand for a number of inches. Every system agrees up to D and diverges after it - which is where almost every conversion error happens. Guide Thou, thee, thy and thine: the rule almost everyone gets wrong Thou is a subject and thee is an object, exactly like I and me. The full paradigm, the verb endings that go with each, and why the mix-up is so visible. Guide What the 13 digits of a South African ID number mean Date of birth, gender, citizenship and a checksum - what each part of a South African ID number encodes, and what a valid number does and does not prove. Guide Why counting syllables is harder than it looks Syllable counters disagree with each other and with you. English spelling hides syllables, some words have two valid counts, and no rule covers every case. Guide How many paving slabs do I need? The maths calculators get wrong Dividing patio area by slab size under-orders, because offcuts rarely fit. Here is the calculation that counts whole slabs and cut pieces separately. Guide Why won't my QR code scan? Contrast, colour and quiet zones Most unscannable QR codes fail for one of three reasons: too little contrast, inverted colours, or no quiet zone. What each is, and how to avoid it. Guide Kilojoules, calories, salt and sodium: reading a food label Two conversions that trip people up on food labels: kilojoules to calories, and salt to sodium. The exact factors, and why sodium looks smaller than salt.