How to Remove the Background from an Image
There are two methods and almost every article pretends there is one. A flood fill removes what matches the background a...
Guides & How-tos · Worked examples · Real numbers
Do it right, with real numbers
Step-by-step how-tos, head-to-head comparisons and honest roundups — every guide worked through with current figures, then backed by a RECATOOLS calculator or AI-directory entry so you can act on it.
510 guides published
17 topic areas
Latest guide Oct 2026
Statistics
35
Health & Wellness
33
Cybersecurity
30
Business
19
Privacy & Data
17
Consumer Tech
14
ASEAN Tech
13
Personality
9
Cloud & Infra
8
Cyber Threat Intel
7
Sustainability
5
Advertisement
How Many Ounces in a Cup? Eight — and That Is Why People Get It Wrong
Eight is correct, for one specific cup out of six in ordinary use. The largest is 57.9% bigger than the smallest, the cu...
How to Work Out How Much to Feed Your Dog or Cat
Almost every feeding mistake starts with the weight you type in. Use the animal in front of you and the sum returns the...
How to Size a Cable: the Six Checks, and the Three People Skip
Picking a cable looks like one lookup — find the current, read the size off a table. That answer is right in a cool plan...
Does Re-Saving a JPEG Make It Worse?
Re-saving a JPEG is nearly lossless at exactly one quality — the one it was already saved at — and roughly forty times c...
Is Rent Really Dead Money? What a Lease Costs You
"Rent is dead money" ends most rent-versus-buy conversations before the arithmetic starts, because it sounds like an acc...
Dilute It Tenfold. The pH Moves One Unit, or None at All.
C1V1 = C2V2 looks like arithmetic but is a physical claim with four assumptions inside it. Dilute a strong acid tenfold...
When Does an HDB Lease Start Affecting Your Loan?
Lease decay gets filed with rising sea levels — real, distant, somebody's problem eventually. But the rule that actually...
Cap Rate, BRRRR and Which Property Metrics Travel
Cap rate, cash-on-cash and net operating income are arithmetic — they work on any building in any currency. BRRRR is not...
We Went Looking for What AI Is Bad At. We Found a Bill Instead.
Every business owner wants a map of where AI is reliable and where it is not. We built five task types — drafting to spe...
We Tested the Prompting Folklore — 474 Answers Later, Nothing Had Changed
Tell the model it is an expert. Offer it a $200 tip. Threaten it. Say please. Add "let's think step by step". We ran all...
Why AI Cannot Spell — What Image, Video and Voice Models Do Instead
A language model emits one symbol at a time, in order. An image model starts from noise and refines the whole canvas at...
Advertisement