# Math in Esperanto: plus, minus, fractions and shapes

Source: https://esperantopedia.org/phrases/math-shapes/
Language: en
Updated: 2026-10-11

> Say 2 + 3 = 5 as du plus tri estas kvin, plus Esperanto words for fractions, percent, decimals, shapes and school maths, with pronunciation.

In Esperanto you read a sum by naming its signs: *2 + 3 = 5* is ***Du plus tri estas kvin.*** The signs are *plus*, *minus*, *oble* "times" and *dividite per* "divided by", and "equals" is *estas*, *egalas* or *faras*. Fractions use the suffix *-on-* (*duono* "half"), the decimal mark is a comma (*komo*), and shapes are nouns in *-o*: *cirklo*, *kvadrato*, *kubo*.

The number words themselves are on the [numbers page](https://esperantopedia.org/grammar/numbers/). Pronunciation guides split words into syllables, with the stressed syllable in capitals.

## How do you read a sum aloud?

Name each sign, then the result. The Fundamento reads the equals sign with *faras* ("makes"): *Du kaj du faras kvar*. PMEG says *estas* and *egalas (al)* are more common today.

| English | Esperanto | Pronunciation | Note |
|---|---|---|---|
| plus, and (+) | *plus*, *kaj* | PLUS, KAJ | *Du plus du* or *du kaj du* |
| minus (−) | *minus* | MI-nus | also the sign of a negative number |
| times (×) | *oble*, *multiplikite per* | O-ble, mul-ti-pli-KI-te per | *trioble kvar* or *tri oble kvar* |
| divided by (÷) | *dividite per* | di-vi-DI-te per | |
| equals (=) | *estas*, *egalas*, *faras* | ES-tas, e-GA-las, FA-ras | *egalas al* also correct; *faras* is the Fundamento's wording |
| squared (²) | *kvadrate* | kva-DRA-te | *tri kvadrate estas naŭ* |
| cubed (³) | *kube* | KU-be | |
| power | *potenco* | po-TEN-co | *la dua potenco de dek* "the second power of ten" |
| square root (√) | *kvadrata radiko* | kva-DRA-ta ra-DI-ko | |

| Written | Esperanto |
|---|---|
| 2 + 3 = 5 | *Du plus tri estas kvin.* / *Du kaj tri faras kvin.* |
| 9 − 4 = 5 | *Naŭ minus kvar estas kvin.* |
| 3 × 4 = 12 | *Trioble kvar estas dek du.* / *Tri multiplikite per kvar faras dek du.* |
| 12 ÷ 4 = 3 | *Dek du dividite per kvar estas tri.* |
| 3² = 9 | *Tri kvadrate estas naŭ.* |
| √16 = 4 | *La kvadrata radiko de dek ses estas kvar.* |

*Oble* attaches to the number before it (*trioble*, *kvinoble*) or stands alone (*tri oble kvar*). The Fundamento has *Kvinoble sep estas tridek kvin*, "five times seven is thirty-five".

*Plus tri* is a *pozitiva nombro* and *minus tri* a *negativa nombro*; zero is *nul*. For comparing, *pli granda ol* is "greater than" and *malpli granda ol* "less than": *Kvin estas pli granda ol tri.* For −10° PMEG gives *minus dek gradoj* or *dek gradoj sub nulo*. See [comparison](https://esperantopedia.org/grammar/comparison/) for *pli* and *ol*.

## What are the words for add, subtract, multiply and divide?

Each operation has a verb, and its outcome has its own noun. Outside technical talk, ReVo says *aldoni* "to add" and *depreni* "to take away" can replace *adicii* and *subtrahi*.

| English | Esperanto | Pronunciation | Note |
|---|---|---|---|
| to add | *adicii*, *aldoni* | a-di-CI-i, al-DO-ni | noun *adicio* |
| to subtract | *subtrahi* | sub-TRA-hi | noun *subtraho* |
| to multiply | *multipliki* | mul-ti-PLI-ki | noun *multipliko* |
| to divide | *dividi* | di-VI-di | noun *divido* |
| sum | *sumo* | SU-mo | result of adding |
| difference | *diferenco* | di-fe-REN-co | result of subtracting |
| product | *produkto* | pro-DUK-to | result of multiplying |
| quotient | *kvociento* | kvo-ci-EN-to | result of dividing |

## How do you say fractions and percent?

A fraction is a number plus the suffix *-on-*, one of that many equal parts. *Kvarono* is an ordinary noun, so three of them are *tri kvaronoj*. See [suffixes](https://esperantopedia.org/grammar/suffixes/) for *-on-*, *-obl-* and *-op-*.

| Fraction | Esperanto | Pronunciation | Note |
|---|---|---|---|
| ½ | *duono* | du-O-no | adjective *duona* "half" |
| ⅓ | *triono* | tri-O-no | |
| ¼ | *kvarono* | kva-RO-no | |
| 1/100 | *centono* | cen-TO-no | |
| ⅔ | *du trionoj* | du tri-O-noj | |
| ¾ | *tri kvaronoj* | tri kva-RO-noj | *Tri kvaronoj de la kuko restas.* |
| 2½ | *du kaj duono* | du kaj du-O-no | |

As a prefix, *duon-* and *kvaron-* join the next word: *duonhoro* "half an hour", *kvaronkilometro* "a quarter of a kilometre". Multiples use *-obl-* and groups *-op-*: *Dudek estas la duoblo de dek.* The table adds groups and percent.

| English | Esperanto | Pronunciation | Note |
|---|---|---|---|
| twice as much | *duoble* | du-O-ble | adjective *duobla*, noun *duoblo* |
| a pair | *duopo* | du-O-po | adverb *duope* "in pairs" |
| percent | *elcento*, *procento* | el-CEN-to, pro-CEN-to | both in ReVo; *procento* also means "interest" on money |

Say the number first, then the plural: *dudek elcentoj* or *dudek procentoj* for 20%. PMEG reads 100% as *cent procentoj/elcentoj*; ReVo marks *pocento* as one to avoid. *La rabato estas dudek elcentoj.* – "The discount is twenty percent."

## How do you say decimals and measurements?

Esperanto uses a decimal comma, not a point: *3,5* is *tri komo kvin* (PMEG). After the *komo*, read the digits one by one.

| Written | Esperanto | Note |
|---|---|---|
| 3,14 | *tri komo unu kvar* | *La nombro pi estas proksimume tri komo unu kvar.* |
| 46,987 | *kvardek ses komo naŭ ok sep* | not "…komo naŭcent okdek sep" (PMEG) |
| 1 250,75 | *mil ducent kvindek komo sep kvin* | comma for decimals, space between thousands (ReVo) |
| 210 × 297 mm | *ducent dek oble ducent naŭdek sep milimetroj* | A4 paper; *oble* joins two dimensions |

A digit after the comma is a *decimalo*. Units follow the number: *kvadrata metro* "square metre", *kuba metro* "cubic metre".

## What are the shapes called in Esperanto?

Flat shapes end in *-o*. ReVo defines *kvadrato* as a right-angled rhombus, a regular quadrilateral.

| English | Esperanto | Pronunciation | Note |
|---|---|---|---|
| circle | *cirklo* | CIR-klo | curve of points equally far from a centre |
| triangle | *triangulo* | tri-an-GU-lo | |
| square | *kvadrato* | kva-DRA-to | adjective *kvadrata* "square" |
| rectangle | *rektangulo*, *ortangulo* | rek-tan-GU-lo, or-tan-GU-lo | both are in ReVo |
| rhombus | *rombo* | ROM-bo | |
| parallelogram | *paralelogramo* | pa-ra-le-lo-GRA-mo | |
| trapezoid, trapezium | *trapezo* | tra-PE-zo | quadrilateral with two parallel sides |
| quadrilateral | *kvarlatero* | kvar-la-TE-ro | |
| pentagon, hexagon | *pentagono*, *heksagono* | pen-ta-GO-no, hek-sa-GO-no | five and six sides |
| polygon | *plurlatero* | plur-la-TE-ro | ReVo marks *plurangulo* as to be avoided |

Solid shapes work the same way. The surface of a ball is a *sfero*; the object itself is a *globo*.

| English | Esperanto | Pronunciation | Note |
|---|---|---|---|
| cube | *kubo* | KU-bo | bounded by six squares; adjective *kuba* |
| sphere | *sfero* | SFE-ro | |
| ball, globe | *globo* | GLO-bo | |
| pyramid | *piramido* | pi-ra-MI-do | |
| cylinder | *cilindro* | ci-LIN-dro | |
| cone | *konuso* | ko-NU-so | |
| prism | *prismo* | PRIS-mo | |
| face | *faco* | FA-co | flat side of a solid |
| edge | *eĝo* | E-ĝo | |

*Kubo havas ses facojn, dek du eĝojn kaj ok verticojn.* – "A cube has six faces, twelve edges and eight vertices." *Kvadrato havas kvar egalajn laterojn.* – "A square has four equal sides."

## Which words describe geometry and measurement?

| English | Esperanto | Pronunciation | Note |
|---|---|---|---|
| point | *punkto* | PUNK-to | |
| straight line | *rekto* | REK-to | endless; a segment is a *streko* |
| angle | *angulo* | an-GU-lo | |
| right angle | *orta angulo* | OR-ta an-GU-lo | *orto* is 90°; ReVo marks *rekta angulo* as one to avoid |
| acute, obtuse angle | *akuta angulo*, *obtuza angulo* | a-KU-ta an-GU-lo, ob-TU-za an-GU-lo | under 90°, between 90° and 180° |
| corner, vertex | *vertico* | ver-TI-co | |
| radius | *radiuso* | ra-di-U-so | |
| diameter | *diametro* | di-a-ME-tro | twice the radius |
| circumference | *cirkonferenco* | cir-kon-fe-REN-co | |
| perimeter | *perimetro* | pe-ri-ME-tro | |
| area | *areo* | a-RE-o | |
| volume | *volumeno* | vo-lu-ME-no | |
| length, width | *longo*, *larĝo* | LON-go, LAR-ĝo | |
| height, depth | *alto*, *profundo* | AL-to, pro-FUN-do | *alto* also the height of a triangle |
| parallel | *paralela* | pa-ra-LE-la | |
| perpendicular | *perpendikulara* | per-pen-di-ku-LA-ra | |

A measurement takes the ending *-n*: *La tablo estas du metrojn longa kaj unu metron larĝa.* – "The table is two metres long and one metre wide." More examples:

- *La sumo de la anguloj de triangulo estas cent okdek gradoj.* – "The angles of a triangle add up to 180 degrees."
- *Por kalkuli la areon de rektangulo, multipliku la longon per la larĝo.* – "To find the area of a rectangle, multiply the length by the width."

## Nombro, numero or cifero: which one do you need?

*Nombro* is the quantity, *numero* is a number used as a label, and *cifero* is the written sign.

| English | Esperanto | Pronunciation | Note |
|---|---|---|---|
| number (quantity) | *nombro* | NOM-bro | *la nombro de lernantoj* "the number of pupils" |
| number (label) | *numero* | nu-ME-ro | ReVo: *numero de paĝo, telefono, bileto* |
| digit | *cifero* | ci-FE-ro | the written sign, 0 to 9 |

*Ĉi tiu nombro havas kvar ciferojn.* – "This number has four digits." *Mi loĝas en ĉambro numero sep.* – "I live in room number seven." PMEG separates the two: *kvara* means three came before, while *numero kvar* is just a label.

## Which words do you need in a maths lesson?

| English | Esperanto | Pronunciation | Note |
|---|---|---|---|
| mathematics | *matematiko* | ma-te-ma-TI-ko | |
| geometry | *geometrio* | ge-o-me-TRI-o | |
| to calculate | *kalkuli* | kal-KU-li | work with numbers to find another number |
| calculator | *kalkulilo* | kal-ku-LI-lo | *kalkul·il·o*, "calculating tool" |
| equation | *ekvacio* | ek-va-CI-o | |
| to solve | *solvi* | SOL-vi | *solvi ekvacion*; noun *solvo* |
| result | *rezulto* | re-ZUL-to | |

*Mi ne povas solvi ĉi tiun ekvacion.* – "I can't solve this equation." *Ĉu mi rajtas uzi kalkulilon?* – "May I use a calculator?" *Kio estas la rezulto?* – "What is the result?" The page on [school and education](https://esperantopedia.org/phrases/school-education/) has the rest of the classroom.

## How are these words built?

The parts never change, so many of these words can be read from their pieces: *tri·angul·o* "three-angle", *kvar·later·o* "four-side", *plur·later·o* "many-side", *kalkul·il·o* "calculate-tool". See [word building](https://esperantopedia.org/grammar/word-building/), and use the [number converter](https://esperantopedia.org/tools/numbers/) for fractions and multiples.

## Common questions

### How do you say plus, minus, times and divided by in Esperanto?

*Plus*, *minus*, *oble* (or *multiplikite per*) and *dividite per*. The equals sign is read *estas*, *egalas al* or, in the Fundamento, *faras*.

### How do you say 2 + 2 = 4 in Esperanto?

*Du plus du estas kvar.* The Fundamento's wording, *Du kaj du faras kvar*, is also correct.

### How do you say half, a third and a quarter in Esperanto?

*Duono*, *triono* and *kvarono*. Three quarters is *tri kvaronoj*, and percent is *elcento* or *procento*.

### How do you say 3.5 in Esperanto?

Write a decimal comma and say *tri komo kvin*, reading each digit after the *komo* separately.

### What is the difference between nombro, numero and cifero?

*Nombro* is a quantity, *numero* is a label such as a room number, and *cifero* is a written digit.

### How do you say circle, square, triangle and cube in Esperanto?

*Cirklo*, *kvadrato*, *triangulo* and *kubo*. A rectangle is *rektangulo* or *ortangulo*, and a sphere is *sfero*.

## Sources

- [PMEG: Matematikaj esprimoj](https://bertilow.com/pmeg/gramatiko/nombroj/matematiko.html) (reading sums, decimal comma, measures)
- [PMEG: Plus kaj minus](https://bertilow.com/pmeg/gramatiko/kunligaj_vortetoj/plus_minus.html)
- [PMEG: O-vortaj nombrovortoj](https://bertilow.com/pmeg/gramatiko/nombroj/o-vortoj.html), [Suffix ON](https://bertilow.com/pmeg/vortfarado/afiksoj/sufiksoj/on.html), [Suffix OBL](https://bertilow.com/pmeg/vortfarado/afiksoj/sufiksoj/obl.html), [Suffix OP](https://bertilow.com/pmeg/vortfarado/afiksoj/sufiksoj/op.html)
- [PMEG: Use of number words (numero)](https://bertilow.com/pmeg/gramatiko/nombroj/vortetoj/uzado.html), [N for measure](https://bertilow.com/pmeg/gramatiko/rolmontriloj/n/mezuro.html), [Auxiliary signs (%)](https://bertilow.com/pmeg/skribo_elparolo/skribo/helposignoj.html)
- ReVo: [plus](https://reta-vortaro.de/revo/art/plus.html), [minus](https://reta-vortaro.de/revo/art/minus.html), [egala](https://reta-vortaro.de/revo/art/egal.html), [-obl-, oble](https://reta-vortaro.de/revo/art/obl.html), [pozitiva](https://reta-vortaro.de/revo/art/poziti.html), [negativa](https://reta-vortaro.de/revo/art/negati.html), [adicii](https://reta-vortaro.de/revo/art/adici.html), [aldoni](https://reta-vortaro.de/revo/art/don.html), [depreni](https://reta-vortaro.de/revo/art/pren.html), [subtrahi](https://reta-vortaro.de/revo/art/subtra.html), [multipliki](https://reta-vortaro.de/revo/art/multip.html), [dividi](https://reta-vortaro.de/revo/art/divid.html), [sumo](https://reta-vortaro.de/revo/art/sum.html), [diferenco](https://reta-vortaro.de/revo/art/difere.html), [produkto](https://reta-vortaro.de/revo/art/produk.html), [kvociento](https://reta-vortaro.de/revo/art/kvocie.html), [potenco](https://reta-vortaro.de/revo/art/potenc.html), [radiko](https://reta-vortaro.de/revo/art/radik.html)
- ReVo: [duono](https://reta-vortaro.de/revo/art/du.html), [triono](https://reta-vortaro.de/revo/art/tri.html), [kvarono](https://reta-vortaro.de/revo/art/kvar.html), [centono, elcento, pocento](https://reta-vortaro.de/revo/art/cent.html), [procento](https://reta-vortaro.de/revo/art/procen.html), [rabato](https://reta-vortaro.de/revo/art/rabat.html), [komo](https://reta-vortaro.de/revo/art/kom.html), [punkto](https://reta-vortaro.de/revo/art/punkt.html), [decimalo, decimala](https://reta-vortaro.de/revo/art/decima.html)
- ReVo: [cirklo, cirkla](https://reta-vortaro.de/revo/art/cirkl.html), [kvadrato, kvadrata](https://reta-vortaro.de/revo/art/kvadra1.html), [rombo](https://reta-vortaro.de/revo/art/romb.html), [paralelogramo](https://reta-vortaro.de/revo/art/parale2.html), [trapezo](https://reta-vortaro.de/revo/art/trapez.html), [pentagono](https://reta-vortaro.de/revo/art/pentag.html), [heksagono](https://reta-vortaro.de/revo/art/heksagon.html), [plurlatero, kvarlatero, latero](https://reta-vortaro.de/revo/art/later.html), [angulo, triangulo, rektangulo, ortangulo, plurangulo](https://reta-vortaro.de/revo/art/angul.html)
- ReVo: [kubo](https://reta-vortaro.de/revo/art/kub.html), [sfero](https://reta-vortaro.de/revo/art/sfer.html), [globo](https://reta-vortaro.de/revo/art/glob.html), [piramido](https://reta-vortaro.de/revo/art/pirami.html), [cilindro](https://reta-vortaro.de/revo/art/cilind.html), [konuso](https://reta-vortaro.de/revo/art/konus.html), [prismo](https://reta-vortaro.de/revo/art/prism.html), [faco](https://reta-vortaro.de/revo/art/fac.html), [eĝo](https://reta-vortaro.de/revo/art/egx.html)
- ReVo: [orta, orto](https://reta-vortaro.de/revo/art/ort.html), [akuta](https://reta-vortaro.de/revo/art/akut.html), [obtuza](https://reta-vortaro.de/revo/art/obtuz.html), [rekta, rekto](https://reta-vortaro.de/revo/art/rekt.html), [streko](https://reta-vortaro.de/revo/art/strek.html), [vertico](https://reta-vortaro.de/revo/art/vertic.html), [radiuso](https://reta-vortaro.de/revo/art/radius.html), [diametro](https://reta-vortaro.de/revo/art/diamet.html), [cirkonferenco](https://reta-vortaro.de/revo/art/cirkon.html), [perimetro](https://reta-vortaro.de/revo/art/perime.html), [areo](https://reta-vortaro.de/revo/art/are.html), [volumeno](https://reta-vortaro.de/revo/art/volume.html), [paralela](https://reta-vortaro.de/revo/art/parale.html), [perpendikulara](https://reta-vortaro.de/revo/art/perpen1.html), [longo](https://reta-vortaro.de/revo/art/long.html), [larĝo](https://reta-vortaro.de/revo/art/largx.html), [alto](https://reta-vortaro.de/revo/art/alt.html), [profundo](https://reta-vortaro.de/revo/art/profun.html)
- ReVo: [nombro](https://reta-vortaro.de/revo/art/nombr.html), [numero](https://reta-vortaro.de/revo/art/numer.html), [cifero](https://reta-vortaro.de/revo/art/cifer.html), [kalkuli, kalkulilo](https://reta-vortaro.de/revo/art/kalkul.html), [ekvacio](https://reta-vortaro.de/revo/art/ekvaci.html), [solvi](https://reta-vortaro.de/revo/art/solv.html), [rezulto](https://reta-vortaro.de/revo/art/rezult.html), [matematiko](https://reta-vortaro.de/revo/art/matema.html), [geometrio](https://reta-vortaro.de/revo/art/geomet1.html)