Thai Numbers 11 to 100 Quiz — Tens, Prices and the Yii Sip Rule (Free Quiz)

If you learned Thai numbers 1 to 10 in Post 03, you already have the foundation for everything in this post. Thai numbers above ten are built from the same nine digits you already know — combined with สิบ (sip — ten) and the pattern of tens. The system is logical, consistent, and learnable in a single session.

There are exactly two things to memorise that break the regular pattern. Everything else follows rules. Learn these two exceptions first and the rest of Thai counting from 11 to 100 becomes a system you can work out rather than a list you have to memorise.

The Tens — 10 to 100

The pattern is clear: every ten from 30 onwards is digit + sip. สามสิบ (sam sip = 30), สี่สิบ (si sip = 40), ห้าสิบ (ha sip = 50). The only exception is ยี่สิบ (yii sip = 20). Once you know this, every ten between 30 and 90 is automatic.

The Teens — 11 to 19

Every teen is sip (ten) + the digit. The only adjustment is that one becomes เอ็ด (et) rather than nueng when it falls at the end of a compound number. So eleven is สิบเอ็ด (sip et), not sip nueng.

The Et Rule — Why 11, 21, 31... All Use Et

The word เอ็ด (et) is an older Tai word for "one" that has been preserved specifically in the final-digit position of compound numbers. When one appears at the end of any number 11 or above, it becomes et.

This rule is consistent without exception from 11 to 91. Every number ending in 1 above ten uses et. Nueng is reserved for standalone one — one person (หนึ่ง คน), one night (หนึ่ง คืน from Post 22), one serving (หนึ่ง ที่ from Post 24) — but never as the final digit in a teen or compound number.

Building Any Number 11 to 99

Once you know the tens and the et rule, building any number is a matter of combining what you already know:

Pattern: [tens word] + [units digit]

Examples: ยี่สิบ สอง = 22 (yii sip song). สามสิบ ห้า = 35 (sam sip ha). ห้าสิบ เจ็ด = 57 (ha sip jet). แปดสิบ เก้า = 89 (paet sip kao).

The only compound that needs extra thought is any number in the twenties, since 20 itself is yii sip rather than song sip. So 22 is yii sip song, 25 is yii sip ha, 28 is yii sip paet. Everything in the twenties just needs you to remember that the tens word is yii sip, not song sip — the units digits attach exactly as they do in every other decade.

Real Prices — Numbers in Daily Thai Life

The most immediate application of numbers 11–100 is prices. Almost every street food item, motorbike taxi fare, and market purchase falls in this range. Prices are stated as number + บาท (baht):

Understanding prices spoken aloud is arguably the most practical skill this post gives you. A market vendor says สามสิบห้าบาท (sam sip ha baht) and you hand over the right money without hesitation. A motorbike taxi driver says สี่สิบบาท (si sip baht) and you know immediately whether that is fair before agreeing.

Connecting Numbers to What You Already Know

Numbers 11–100 appear throughout the vocabulary you have already learned in this series. Post 22 introduced หนึ่ง คืน (nueng khuen — one night) and สอง คืน (song khuen — two nights). With numbers up to 100, you can now say any number of nights. Post 12 covered Thai spice levels where vendors often quote prices for different spice-level dishes using these exact numbers. Post 19 introduced taxi fares — almost all of which sit between 30 and 90 baht for short journeys.

The number system compounds across everything. Knowing numbers 1–10 let you say how many you wanted. Knowing numbers 11–100 lets you understand and state prices, distances, times, ages, and quantities that cover the full range of practical daily life in Thailand.

Fifteen quiz questions covering the full range of 11 to 100 — with a focus on the two exceptions and the numbers that appear most in daily transactions. All with audio. 🔢