Tests and worked solutions
Every tool with a test-yourself mode: a fresh exam-style question dealt with clean numbers, the answer revealed part by part, and the working stepped through line by line so you can find exactly where you diverged.
Interactive tools
Option payoff diagrams
Price calls and puts with Black-Scholes, combine up to four legs plus the underlying, and see breakevens, max profit and max loss instantly. Made for CM2, SP5 and CFA revision, with name-the-position and draw-the-payoff test modes.
Binomial option pricing
The Cox-Ross-Rubinstein tree drawn live: European and American calls and puts, early-exercise nodes highlighted, and convergence to Black-Scholes as the steps multiply. Includes a test-yourself mode with worked solutions.
Bond price and yield calculator
Price from yield or yield from price, with running yield, duration, modified duration and convexity. Fixed interest for CM1, SP5 and CFA, with a test-yourself mode and worked solutions.
Annuity calculator
Annuities-certain in proper notation: arrears, due, continuous and increasing values, accumulations, and every equivalent way of quoting an interest rate. Core CM1, with a test-yourself mode and worked solutions.
Run-off triangles
Edit a cumulative claims triangle and watch the chain ladder complete it, with expected loss ratio and Bornhuetter-Ferguson reserves side by side — plus every formula, an Excel walk-through and a test-yourself mode with worked solutions. CS2 reserving.
No-claims discount simulator
The CS2 Markov chain classic: transition matrix, year-by-year convergence and the stationary distribution, with the long-run average premium in pounds. Includes a test-yourself mode with worked solutions.
Kaplan-Meier playground
Edit a survival dataset with censoring toggles and watch the product-limit estimate, the Nelson-Aalen overlay and the full risk-set table rebuild live. CS2, with a test-yourself mode and worked solutions.
Credibility theory calculator
Edit a claims grid by risk and year and get the EBCT Model 1 variance components, the credibility factor Z and every risk's blended premium, working shown. CS1, with a test-yourself mode and worked solutions.
Linear regression playground
Drag points and the least squares line chases them, residuals hanging in gold, with b, a, r and R squared recomputed live from Sxx, Sxy and Syy. CS1 and any stats course, with a test-yourself mode and worked solutions.