Penny Impact

What really happens if we get rid of the penny? Penny Impact is a hands-on lab for life without 1¢ coins. Explore how cash rounding affects everyday purchases, small businesses, and classroom discussions — using your own data, not just theory. Everyday Impact • Model a “typical” purchase in the Everyday Impact tab • Adjust how often you shop, and how often you use cash vs card • See how different rounding rules (nearest 5¢, always up, always down) change what you actually pay • Get plain-English summaries like “over a year this is about a snack or coffee” Build a Real Receipt • Open the Receipt playground to build a full receipt, item by item • Change prices and watch the total jump in 5¢ steps • Switch between cash and card to see when rounding does — and doesn’t — matter Journal & Coach (New) Turn Penny Impact into your personal rounding lab. • Log real cash purchases in the Rounding Journal • Track where you saved a few cents and where you paid a bit extra • See totals for “saved”, “overpaid”, and your net impact from rounding • Open the Rounding Coach to get a smart, story-style summary based on your own data: – View your data as a customer, a store, or a teacher – Switch “Overall / Fair / Habits / Rules” to change the kind of insight you get – See a simple confidence meter that tells you how much data the coach is using – Use a “What if I used less cash?” slider to estimate how changing your habits would change your net rounding impact All analysis runs on your device using your own journal entries. No accounts, no ads. For Teachers & Students Use real-world numbers to make math and civics feel less abstract. • Worksheet generator: create printable or on-screen rounding exercises with answer keys • Mix different rounding rules for “Which policy is fair?” discussions • Use your own logs as a tiny dataset: saved vs overpaid counts, net impact, and rule comparisons • Great for upper elementary through high school when talking about money, rounding, or consumer fairness For Small Businesses & Cashiers Penny Impact also includes tools “from behind the counter”: • Explore how different rounding policies might affect daily totals • Compare “nearest 5¢” vs “always up” vs “always down” from the store’s perspective • Use examples to help explain your policy to staff or customers For the Curious (and the Nerdy) The Economics section collects simple explanations and thought experiments: • Why some countries dropped 1¢ coins and how they adjusted • How rounding rules can be designed to be fair on average • Ways to talk about rounding with friends, family, or in public meetings Privacy & Design • No sign-up, no tracking, no ads • All logs and calculations stay on your device • Designed for iPhone and iPad with a clean, readable layout Whether you’re a curious shopper, a teacher, a small business owner, or just a math nerd who loves “what if?” questions, Penny Impact gives you a practical way to explore life without pennies — one receipt at a time.