Algorithms
Algorithms is a set of step-by-step rules that tell you how to solve a problem the same way each time.
A recipe card tells you each step in order: measure flour, add eggs, mix, then bake. You follow the same steps every time you want the same result. Each step depends on the one before it. That is how an algorithm works — a fixed set of steps that always leads to the same outcome.
Explaining algorithms by grade level
Think about making change with coins. You pick the biggest coin first, then the next biggest, until you have the right amount. Those steps are an algorithm. Following the same steps each time helps you get the answer faster.
Projects that explore algorithms
An algorithm solves a problem the same way each time by following a fixed set of step-by-step rules. In this experiment, a brute-force program tests every possible combination of pennies, nickels, dimes, quarters, and half-dollars to count how many ways make change for a dollar. It works — but runs very slowly. When you search for patterns in the results, you find that the five-coin problem connects to simpler four-coin and three-coin problems. A new program built on those patterns runs over 26,000 times faster, solving the ten-thousand-dollar problem in less than an hour.
Can a set of step-by-step rules predict where a stock price is headed? You gather earnings data from SEC filings for over 108 stocks across different sizes and industries. Each financial indicator gets a score from -1 to +1, and those scores feed into an overall equation — the same fixed rules applied the same way each time. When you test the system's predictions over periods from 3 months to 5 years, it identifies profitable stocks about 95% of the time. Over a one-year test period, the picks return 64% on the investment with less than 5% prediction error.