# MB-88F Fractional Calculator — Exact RPN fraction calculator > Exact RPN fraction calculator (iPhone/iPad app by Maxwell Bayman.) - Source: https://appshunter.io/ios/app/mb-88f-fractional-calculator/id6785204791 (this page in markdown: same URL + `.md`) - Developer: [Maxwell Bayman](https://appshunter.io/developer/6784355391) - Category: Utilities, Productivity - Price: Free with in-app purchases - Age rating: 4+ - Requires: iOS 16.0 · 1 MB - Languages: American English - Released: 2026-07-05 - Data updated: 2026-07-08 - User reviews in markdown: https://appshunter.io/ios/app/mb-88f-fractional-calculator/id6785204791/reviews.md ## What is MB? MB 88F is a calculator that thinks in exact fractions. Every value is kept as a whole-number numerator over a whole-number denominator, so the math never drifts. 1/3 + 1/6 is exactly 1/2, never 0.4999. Whether you're cutting a board, scaling a recipe, piecing a quilt, or checking fraction homework, the answer stays exact — and inches and millimeters relate by the exact definition 1 in = 25.4 mm, so conversions never lose a thousandth. NEW TO RPN? MB 88F uses Reverse Polish Notation: you key the numbers first, then the operation — 3, ENTER, 4, + instead of 3 + 4 =. No equals key, no parentheses to juggle. It's the input style engineers and HP-calculator fans have sworn by for decades because it makes real calculations flow. If it's new to you, it clicks in about a minute, and a built-in manual, key index, and cheat sheet are right there to walk you through it. WHAT IT DOES • Exact fraction arithmetic — add, subtract, multiply, divide, always reduced to lowest terms • Mixed-number entry: key 2 SPC 1 b/c 2 for 2 1/2 • Tape-measure rounding to 1/8, 1/16, 1/32, or 1/64 — and TRU to restore the exact value • Fraction ↔ decimal conversion both ways • Exact unit tagging and conversion: inches, feet, millimeters, meters • Feet read as feet plus fractional inches (22.5 ft → 22 ft 6 in) POWER KEYS • 1/x, x², and √x for diagonals and right-triangle math • ½x to instantly find a centerline, 2x to double it • Store/recall memory (STO/RCL) to hold and reuse a value • History tape — tap the display to see your last 100 results and pull any of them back into the stack • Last-X recall, stack roll, and swap MADE TO LIVE WHERE YOU WORK • Universal — one app, built for both iPhone and iPad • Your stack, memory, and history are saved between sessions — pick up right where you left off • 11 color themes • Optional thousands separator and fixed decimal places • Built-in user manual, key index, and cheat sheet • Works 100% offline. No account, no ads, no tracking, no data collected — ever. Try it free for 2 days, then unlock the full app forever with a single one-time purchase — no subscription. Woodworkers, machinists, carpenters, and framers rely on it — and so do quilters and sewists, cooks scaling recipes, students working through fraction homework, and anyone who'd simply rather see 3/4 than 0.75. If you think in fractions, MB 88F keeps them exact. ## Pricing and in-app purchases Base price: Free. **One-time purchases** | Purchase | Price | Type | | --- | --- | --- | | Full Version | $3.99 | one-time | ## Version history (last 2 releases) ### 1.1 — 2026-07-06 • iPad support — MB 88F is now a universal app with a layout built for the big screen • History tape: tap the display to see your last 100 results, and tap any line to pull it right back into the stack • Your work now survives relaunch — the stack, memory register, and history are saved automatically • Tap a value's active unit key to remove the tag and go back to a plain number • Reliability improvements under the hood ### 1.0.1 — 2026-07-05 No release notes. --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-08.*