2.5 Numbers, Dates, Time & Measurement
Key Takeaways
- Cardinal numbers are invariable except uno and the hundreds: veintiuna sillas, doscientas personas.
- Ciento shortens to cien before a noun and before mil and millones, but stays ciento in 101 through 199.
- Dates use cardinal numbers and the order day-month-year: el 15 de marzo de 2026, with primero the only ordinal.
- Clock time uses ser plus the feminine article agreeing with the hour: es la una, son las tres y media.
- Spanish separates decimals with a comma and thousands with a period in most varieties: 1.500 personas, 3,75 metros.
2.5 Numbers, Dates, Time & Measurement
Numbers are where a listening section punishes casual preparation. A train announcement gives a platform, a departure time in the 24-hour clock, and a check-in deadline in minutes — three numerical facts inside twenty seconds of audio, played once. Reading them slowly on a page is a different skill from catching them at speed, so learn the forms cold.
1. Cardinal Numbers and Their Agreement
Most cardinals are invariable. Only two families agree.
| Number family | Agreement behaviour | Example |
|---|---|---|
| uno and compounds | Shortens to un before masc. noun; becomes una before fem. | veintiún libros, veintiuna sillas, treinta y un días |
| Hundreds 200–900 | Agree in gender | doscientos hombres, doscientas mujeres, quinientas páginas |
| Everything else | Invariable | cuatro casas, mil personas |
Ciento / Cien / Mil / Millón
- cien before a noun or before mil / millones: cien euros, cien mil habitantes, cien millones.
- ciento in 101–199: ciento uno, ciento cincuenta.
- mil is invariable and takes no article: mil personas, dos mil euros (never un mil).
- millón is a noun and requires de before another noun: un millón de habitantes, tres millones de euros.
Irregular spellings worth memorizing because they are audibly distinct: quinientos (500), setecientos (700), novecientos (900). Note that they are not built regularly from cinco, siete, nueve.
2. Ordinal Numbers
| Ordinal | Form | Note |
|---|---|---|
| 1st | primero / primera | Shortens to primer before a masc. sing. noun |
| 2nd | segundo/a | |
| 3rd | tercero / tercera | Shortens to tercer before a masc. sing. noun |
| 4th–10th | cuarto, quinto, sexto, séptimo, octavo, noveno, décimo | Agree fully |
Above tenth, Spanish generally abandons ordinals in everyday speech and uses cardinals after the noun: el siglo veintiuno, el piso quince, Alfonso XIII (trece).
3. Dates
Format: el + cardinal + de + month + de + year. Months are not capitalized.
- el 15 de marzo de 2026 — read aloud el quince de marzo de dos mil veintiséis
- Only the first of the month uses an ordinal: el primero de enero (many varieties also accept el uno de enero).
- Numeric dates run day/month/year: 5/8/2026 is 5 August, not 8 May. This inversion is a genuine comprehension trap in schedules and advertisements.
- Years are read as a single number: 1998 = mil novecientos noventa y ocho, never diecinueve noventa y ocho.
Asking and answering:
- ¿Cuál es la fecha de hoy? / ¿A cuántos estamos? -> Estamos a doce de junio.
- ¿Qué día es hoy? -> Hoy es jueves. (Days are also lower-case.)
4. Telling Time
Frame: ser + feminine definite article agreeing with the hour.
| Time | Spanish |
|---|---|
| 1:00 | Es la una. (singular!) |
| 3:00 | Son las tres. |
| 3:15 | Son las tres y cuarto. |
| 3:30 | Son las tres y media. |
| 3:45 | Son las cuatro menos cuarto. / Son un cuarto para las cuatro. |
| 3:50 | Son las cuatro menos diez. |
- At a time uses a: La clase empieza a las nueve.
- Parts of the day use de with a stated hour and por without one: a las ocho de la mañana, but estudio por la mañana.
- Schedules, transport, and official announcements use the 24-hour clock: el tren sale a las catorce horas y quince minutos = 2:15 p.m. Expect this in Section II announcements.
- en punto = on the dot; y pico = a little past.
5. Punctuation, Measurement, and Quantities
| Convention | Spanish practice | Example |
|---|---|---|
| Decimal separator | Comma in most varieties | 3,75 metros |
| Thousands separator | Period or thin space | 1.500 personas |
| Percentages | Take an article | el 20 por ciento de los alumnos |
| Temperature | Celsius | Hace 32 grados. |
| Distance | Kilometres, metres | a 40 kilómetros de la costa |
| Weight | Kilos, gramos | medio kilo de tomates |
| Currency | Follows the number | veinte euros, cien pesos |
Mexican and much of Central American usage follows the English convention (period for decimals), so a passage may show either. Read the surrounding context rather than assuming.
Approximation and Fractions
- unos / unas + number = about: unas treinta personas
- alrededor de, aproximadamente, cerca de = approximately
- la mitad (half), un tercio (a third), un cuarto (a quarter), el doble (double), el triple (triple)
- docena (dozen), decena (about ten), centenar (about a hundred), millar (about a thousand)
6. Listening Drill: Catching Numbers at Speed
When a Section II announcement plays, write only digits and one abbreviation per fact:
Audio: "El vuelo 328 con destino a Quito, previsto para las dieciséis
horas y cuarenta minutos, saldrá de la puerta B12 con un retraso
de veinticinco minutos."
Notes: vuelo 328 / QUI / 16:40 / B12 / +25
Five facts, five tokens, no sentences. Any question the item writer asks — flight number, destination, gate, delay, new departure time — is answerable from that line.
7. Worked Items
Item 1. En el auditorio había ________ personas. (A) doscientos (B) doscientas (C) dos cientas (D) doscienta
Reasoning: Hundreds agree in gender with the noun, and personas is feminine plural. (B).
Item 2. La reunión comenzará ________ una de la tarde. (A) a las (B) a la (C) son las (D) en la
Reasoning: One o'clock is singular, and at a time requires a. (B).
Item 3. La ciudad tiene más de un millón ________ habitantes. (A) que (B) en (C) de (D) con
Reasoning: Millón is a noun and requires de before the counted noun. (C).
Which sentence uses number agreement correctly?
An announcement states that a train departs "a las catorce horas y treinta minutos." What time is that on a twelve-hour clock?
A Spanish advertisement lists an event date as 7/9/2026. In standard Spanish convention, what date is this?