FROM MAXY McMAXFACE · IPHONE + IPAD
A standard calculator that thinks in exact fractions.
1/3 + 1/6 is exactly 1/2 — never 0.4999. Type it the normal way, press equals, and get an exact fraction. Nothing new to learn.
Free 2-day trial · $3.99 once · no subscription
01 — THE NORMAL WAY
Key it like you'd say it. Press equals.
There's nothing to learn here — MB-89F works like every calculator you've ever used. Key 3 b/c 4, plus, 1 b/c 2, press =, and the answer appears: 1 1/4. Exact, reduced, done.
Operations chain left to right as you go, and pressing = again repeats the last one — handy for stepping a measurement along a wall. A built-in manual, key index, and cheat sheet are right there if you ever want them.
Prefer RPN? MB-89F has a sibling — MB-88F — the same exact-fraction engine on a classic Enter-key stack. Meet MB-88F →
3 b/c 4 + 1 b/c 2 = → 1 1/4
# mixed numbers? key 2 1/2 as:
2 SPC 1 b/c 2 → 2 1/2
# and it stays exact:
1b/c3 + 1b/c6 = → 1/2 (never 0.4999)
Type it like you'd say it
Three-quarters plus one-half — the keys follow the sentence in your head. Mixed numbers too: 2 SPC 1 b/c 2 is 2 1/2.
Press equals
The one key every calculator user already knows. Chain operations left to right; press = again to repeat the last one.
It never drifts
Every value is a whole-number numerator over a whole-number denominator, always reduced to lowest terms. Exact stays exact.
02 — BUILT FOR REAL WORK
From the tape measure to the saw.
Tape-measure rounding 1/8 · 1/16 · 1/32 · 1/64
Round any result to the fraction your tape actually shows — then hit TRU to restore the exact value underneath. The math never drifts; only the display does.
Exact units 1 in = 25.4 mm
Tag values as inches, feet, millimeters, or meters and convert without losing a thousandth. Feet read the way you say them: 22.5 ft → 22 ft 6 in.
Power keys 1/x · x² · √x · ½x · 2x
Diagonals and right-triangle math, instant centerlines and doubles, store/recall memory — and a history tape holding your last 100 results. Tap the display to bring any of them back.
Made to live where you work 100% offline
No account, no ads, no tracking — ever. Your value, memory, and history are saved between sessions. 12 color themes, optional thousands separator and fixed decimal places. One app, built for both iPhone and iPad.
03 — WHO IT'S FOR
If you think in fractions, this is your calculator.
- Woodworkers, machinists, carpenters, and framers
- Quilters, sewists, and cooks scaling recipes
- Students working through fraction homework
- Anyone who'd simply rather see 3/4 than 0.75
Two days free. Then $3.99, once.
Try everything free for 2 days, then unlock the full app forever with a single one-time purchase. No subscription, no recurring charges — like software used to work.