I need to ensure accuracy. Let me confirm the formation of numbers in Thai. For example, numbers 11-19 are formed by สิบเอ็ด (11) to สิบเก้า (19). From 20 to 99, it's the tens digit followed by สิบ (e.g., 20 = ยี่สิบ, 30 = สามสิบ). Then the ones digit is added. However, some numbers have different pronunciation: like 30 is สามสิบ (sam sip), 40 is สี่สิบ (see sip), etc.