Mathematics — Numbers

Subtopic: Use of Ordinal Numbers to Identify Position

Today we learn about ordinal numbers. Ordinal numbers tell the position of something in a row or order. Examples: first, second, third, fourth, etc.

How to write ordinal numbers (easy rules)

- Ordinals can be written as words (first, second...) or with a small ending after the number (1st, 2nd, 3rd, 4th).
- Rule for endings: numbers ending in 1 → st, ending in 2 → nd, ending in 3 → rd, others → th.
- Important exception: 11, 12 and 13 always use th (11th, 12th, 13th), even though they end with 1, 2, 3.

Examples from school (Kenyan context)

• You are in a queue for the school lunch. If you are third in line, you are third (3rd).
• At a sports day race, the runner who finishes first wins a medal — the first (1st) place gets gold.
• In the classroom, if teachers call names in order, the student called fourth stands up for the answer — that student is fourth (4th).

Practice activities (do them yourself)

1. Write the word form: 6 → _______
2. Write the short form: fourth → _______
3. Which is correct: 11st or 11th? _______ (explain in one sentence)
4. In a line of 5 pupils, Juma is second. What position is he? _______
5. Match the pictures to the ordinal word:
   🚶‍♂️ 🚶‍♀️ 🚶‍♂️ — label: _______ 🏃‍♀️ 🏃‍♂️ — label: _______

Answers

• 1: sixth
• 2: 4th
• 3: 11th — because 11 is an exception and uses "th"
• 4: He is second (2nd)
• 5: First picture: third (if 3 people and you label the last as third) — second picture: second (if 2 people, the one behind may be second). (Teacher: ask the pupil to say which person they mean and write the correct ordinal.)

Well done! Practice ordinals every day and you will learn them quickly.