Practical guides, how-tos and comparisons to get the most out of our free online tools.
Long division breaks a big division into a repeating four-step cycle. Learn the divide-multiply-subtract-bring-down loop and how to read the remainder, with a worked example.
Lena Hoffmann · 4 min read
Learn how binary place values work and convert binary to decimal and hexadecimal by hand, with clear worked examples.
Daniel Okonkwo · 4 min read
PEMDAS and BODMAS are two names for one rule that fixes the order you evaluate a math expression — so everyone gets the same answer. Learn the rule with a worked example.
Lena Hoffmann · 3 min read
Learn how to work out overtime pay: multiply your hourly rate by 1.5 for time-and-a-half, apply the weekly threshold, and handle double-time correctly.
Camille Laurent · 3 min read
Customer lifetime value estimates the total worth of a customer over the whole relationship. Learn the formula, why margin matters, and how to use it.
Daniel Okonkwo · 3 min read
Ordinal numbers show position, cardinal numbers show quantity. Learn the difference and how each language forms ordinals differently.
Lena Hoffmann · 2 min read
APR and APY both describe a yearly rate, but only APY includes compounding. Here's what each means and which one actually matters for savings and loans.
Camille Laurent · 2 min read
BMI groups weight into ranges relative to height. Here's what counts as healthy, how to calculate it, and the limits of the number.
Sofia Nunes · 2 min read
Weight loss comes down to a calorie deficit. Here's how to estimate your maintenance calories, set a safe deficit, and turn it into a daily target.
Sofia Nunes · 3 min read
The income-multiple and 28/36 rules give you a ceiling in minutes. Here's how to work out an affordable price from your income, debts and down payment.
Camille Laurent · 3 min read
Your savings rate decides how fast you reach financial independence. See how to calculate it, what benchmarks to aim for, and why it beats investment returns.
Camille Laurent · 3 min read
VAT is a percentage added to a price. Here's how to add VAT to a net price, remove it from a gross price, and find the tax amount — with examples.
Camille Laurent · 3 min read