TradingHow to calculate liquidation price for a leveraged positionLearn the liquidation price formula for isolated-margin long and short futures positions, with worked BTC examples at 10x and 50x leverage and how maintenance margin changes the result.TradingThe position sizing formula, with worked examplesThe position sizing formula explained step by step: account risk, stop distance and units to buy, with worked stock and crypto examples, fees, and how leverage fits in.InvestingCompound interest with monthly contributions, explainedHow compound interest works when you add money every month: the formula, a year-by-year example of $5,000 plus $300 a month at 7%, and why time matters more than the rate.Food businessFood cost percentage formula, with worked examplesHow to calculate food cost percentage two ways: per dish from your recipe, and for a whole period from inventory. Worked burger and latte examples, plus how to set menu prices.Small businessBreak-even analysis: a worked example for small businessesA step-by-step break-even analysis example for a small business: fixed vs variable costs, contribution margin, break-even units and revenue, target profit, and what-if price changes.Personal financeDebt snowball vs avalanche: a side-by-side exampleDebt snowball vs debt avalanche compared with a real worked example: three debts, one monthly budget, payoff order, months to debt-free and total interest for each method.Small businessHow much do Etsy fees take? A worked calculationEtsy's listing, transaction and payment processing fees explained with worked examples for a $10 and a $30 item, how shipping is included, and how to price so fees don't eat your profit.Small businessHow to calculate overtime pay, step by stepStep-by-step overtime pay calculation: total weekly hours from shifts and breaks, the 40-hour FLSA rule, time-and-a-half math, overnight shifts and common payroll mistakes.Trading1% a day": what the compounding math really saysWhat 1% a day really compounds to in a year (about 37.8x), how fast losses compound too, why fees and losing days break the curve, and how to use the math sensibly.Small businessMargin vs markup: the difference that changes your pricesMargin vs markup explained with formulas and worked examples: pricing a $12 product for 40% margin vs 40% markup, converting between them, and the pricing mistake it causes.Small businessReorder point and safety stock: formulas with examplesHow to calculate reorder point and safety stock: lead-time demand, the max-minus-average method and the service-level (statistical) method, with worked examples for a small shop.TradingRisk-reward ratio and the win rate you need to break evenHow to calculate risk:reward, the break-even win rate for any ratio, and trade expectancy in R, with worked examples and a table showing why a 40% win rate can be profitable.TradingHow much gain do you need to recover from a loss?Why a 50% loss needs a 100% gain to break even: the loss recovery formula, a full table from 5% to 90%, worked portfolio examples and what it means for risk management.InvestingThe 4% rule and how to calculate your FIRE numberHow to calculate your FIRE / retirement number with the 4% rule (25x expenses), what the rule is based on, its limitations, and a worked example of years to financial independence.Personal financeMortgage amortization and the power of extra paymentsHow mortgage amortization works, the monthly payment formula, a year-by-year schedule for a $300,000 loan at 6.5%, and how $100, $200 or $500 extra a month changes payoff time and interest.