By NikolaEU · Tested on macOS 15.5 with Numi 3.31 · Published July 23, 2026 · Last updated July 23, 2026

The Complete Numi Syntax Reference

Numi accepts standard arithmetic operators, worded equivalents like plus and times, percentage forms with the percent symbol, assignment with an equals sign, conversion with the keyword in, and a compact function library covering rounding, roots, and basic trigonometry. Everything below is organized by category, with the exact forms that parse and the near-misses that don’t. Tested against Numi 3.31.

Arithmetic operators

Operator	Worded form	Example	Notes
+	plus, and	120 + 45	Also concatenates compatible units
-	minus, less	500 - 120	Doubles as a negative sign and a date separator
*	times, multiplied by	6 * 85	x between numbers also works in most contexts
/	divided by, over	340 / 4	Also forms compound units, as in km/h
^	to the power of	2 ^ 10	** is accepted in some builds
%	mod	17 mod 5	Modulo only where no percentage reading fits
( )	—	(120 + 45) * 3	The only reliable way to override precedence

Precedence follows standard mathematics regardless of whether you type symbols or words. 10 plus 5 times 2 returns 20, not 30, because “times” binds tighter than “plus” exactly as * binds tighter than +. Worded input reads left to right to a human and doesn’t to the parser, which is the single most common source of a result that looks wrong. Parentheses settle it every time.

Percentages

Percentages are the highest-traffic feature in the app and the one with the most context-dependent behavior. Four forms cover essentially everything.

Form	Example	Returns	Reading
Percent of	15% of 82	12.3	Plain percentage of a value
Additive	200 + 15%	230	Applies the percentage to the left value
Subtractive	84.99 - 30%	59.49	Discount off the left value
Multiplicative	240 * 15%	36	Same as percent of, written symbolically

The additive row is the one that surprises people arriving from a basic calculator. 200 + 15% does not add the number 15 or the number 0.15. It reads the percentage against the left operand and returns 230, which is almost always what someone typing that line meant. It’s also why tax and tip lines read so cleanly: 68.40 + 18% is the whole calculation.

Chained percentages compound in sequence rather than summing. 100 + 10% + 10% returns 121, not 120, because the second percentage applies to 110. That’s mathematically correct and occasionally not what someone intended, particularly for stacked discounts, so it’s worth writing out explicitly when the distinction matters.

Assignment and references

Keyword	Example	What it does
=	rate = 85	Stores a value under a name for later lines
sum	sum	Totals the contiguous block of result lines above
total	total	Equivalent to sum in most positions
prev	prev * 1.2	Refers to the result of the line directly above

Assignment accepts any evaluable expression on the right side, including one referencing earlier variables, and the stored value carries its unit. distance = 5 km stores a length, not the number five, so every downstream line inherits unit checking.

Naming matters more than it should. Variables resolve last in the parser’s lookup order, after keywords, currencies, units, and date words, so in, m, s, h, and three-letter currency codes like try and cad all lose to their dictionary meanings. Four characters minimum, never a measurement word, and a silent blank line is usually a collision rather than a bug in Numi.

Units and conversion

The conversion keyword is in. The words to and as work identically in most positions, so pick whichever reads better.

12 km in miles
2 cups to grams
340 eur as usd
distance in feet
18 gb / 40 mbps in minutes

The last line is unit algebra rather than simple conversion. Gigabits divided by gigabits-per-second cancels to seconds, which then converts to minutes. This works because compound units like mbps resolve to a composite of a data unit and a time unit, and the evaluator checks compatibility at each node. When units don’t cancel to something compatible with the requested output, the line returns nothing rather than a meaningless figure.

Unit names accept multiple spellings that all canonicalize to one internal unit. km, kilometer, kilometers, and kilometres are the same thing to the parser. Ambiguous short forms are the exception worth avoiding: write min and sec rather than m and s, since m can read as meters, minutes, or million depending on neighbors.

Currency specifics

Currency codes and symbols both parse. $50, 50 usd, and 50 dollars all resolve. Symbol placement binds to the adjacent number, so $50 and 50 $ work while doubled symbols don’t.

Rates are fetched rather than frozen, which means a saved document’s converted totals recompute on reopening. For a forward-looking budget that’s correct behavior. For a record of what something cost on a given date, store the converted result as a plain number instead. Anyone using a natural language calculator for Mac for invoicing should also check the rate’s last refresh before a figure goes anywhere official.

Dates and durations

Pattern	Example	Returns
Date difference	days between mar 1 and jul 4	A day count
Date offset	today + 45 days	A future date
Duration addition	3 hours + 45 min	A normalized duration
Duration conversion	2.5 hours in minutes	A converted duration
Rate against duration	85/hour * 6.5 hours	A plain value, hours cancel

Duration math is where mixed abbreviations cause the most trouble. 5 m + 30 s may resolve m as meters and fail on incompatible units, while 5 min + 30 sec is unambiguous. The extra two characters are worth typing every time.

Business-day arithmetic, holiday calendars, and timezone-aware date math are outside what this format handles. Those belong in a calendar tool or a spreadsheet with a proper date library.

Functions

Function	Example	Purpose
round	round(12.487)	Nearest whole value, with optional precision argument
ceil / floor	ceil(4.2)	Round up or down unconditionally
sqrt	sqrt(144)	Square root
abs	abs(-40)	Absolute value
min / max	max(120, 340, 85)	Smallest or largest of the arguments
log / ln	log(1000)	Logarithms, base ten and natural
sin / cos / tan	sin(45)	Trigonometry, check the angle mode first

Arguments sit inside parentheses, separated by commas where a function takes several. That comma is an argument delimiter rather than a thousands separator, which the tokenizer distinguishes by context. Writing max(1,200, 340) is genuinely ambiguous and worth avoiding by dropping the thousands comma entirely. This is one of the few places where a text calculator for Mac asks you to write less naturally than you’d speak.

Number formats and constants

• Thousands separators are tolerated inside numbers: 4,200 reads as four thousand two hundred.
• Scientific notation works in the usual form, as in 1.2e6.
• Hexadecimal and binary parse with standard prefixes, and base conversion follows the same in keyword pattern.
• Constants including pi and e resolve by name, which is another reason not to use single letters as variable names.
• Negative values work as expected, though wrapping them in parentheses inside a larger expression removes any ambiguity with subtraction.

What doesn’t parse

The honest half of a syntax reference. These forms return nothing, tested on 3.31:

• Numbers spelled as words. twenty percent of eighty needs digits.
• Conditional logic. There’s no if-then construct, so threshold-dependent values must be split into separate labeled lines.
• Solving for unknowns. solve x + 15 = 40 is symbolic algebra and outside scope. Numi evaluates fixed expressions.
• User-defined functions. You can’t define a reusable operation and call it with different arguments.
• Referent tracking across clauses. add 15% then subtract 10% of the original requires knowing what “the original” points at, and the parser has no such memory.
• Statistical and matrix work. Distributions, regressions, and matrix operations aren’t in the library and aren’t intended to be.

The failure mode throughout is silence rather than an error message, which is the app’s least helpful behavior. A blank line means the parser found nothing it could execute, and it won’t tell you which token defeated it. Rewording a clause into shorter lines usually isolates the problem faster than staring at the original, and splitting one long sentence into two named steps in Numi app fixes a surprising share of them.

Five habits that prevent most syntax problems

1. Use digits, never spelled-out numbers.
2. Name variables with four or more characters that aren’t unit or currency abbreviations.
3. Add parentheses whenever a line mixes worded and symbolic operators.
4. Spell out ambiguous units: min over m, sec over s.
5. Split long clauses into two lines joined by a named variable, which parses more reliably and reads better later.

Those five eliminated nearly every parsing problem across a week of daily use with Numi mac. What remained were capability gaps rather than phrasing issues, and no amount of rewording adds a feature that isn’t there.

Frequently asked questions

Written and tested by NikolaEU on macOS 15.5 with Numi 3.31.