Welcome to the World of Numbers!

In this chapter, we are going to learn all about Numbers, Ordinals, and Measurements. Numbers are like a secret code that helps us talk about how many things we have, how big they are, and what order they are in. Whether you are counting snacks, measuring your height, or talking about your rank in a race, these words will help you speak English like a pro!

1. Cardinal Numbers (Counting to \(1,000\))

Cardinal numbers are the numbers we use for counting things (like \(1, 2, 3\)). Let’s look at how we build bigger numbers as we move from ป.4 to ป.6.

Counting to \(100\) (ป.4)

You probably remember the basics, but pay attention to the spelling of the "ty" numbers:

  • Twenty (\(20\)), Thirty (\(30\)), Forty (\(40\)) — Watch out! There is no "u" in forty!
  • Fifty (\(50\)), Sixty (\(60\)), Seventy (\(70\)), Eighty (\(80\)), Ninety (\(90\))

Counting to \(500\) (ป.5) and \(1,000\) (ป.6)

To say numbers bigger than \(100\), we just say the number of "hundreds" first.

The Pattern: [Number] + hundred + and + [Smaller number]

  • \(101\) = one hundred and one
  • \(250\) = two hundred and fifty
  • \(500\) = five hundred
  • \(782\) = seven hundred and eighty-two
  • \(1,000\) = one thousand

Quick Tip: Don't add an "s" to the word hundred when you are saying a specific number. Say "three hundred", NOT "three hundreds".

Key Takeaway: Once you know \(1\)–\(100\), you just need to add the word "hundred" to reach \(1,000\)!

2. Ordinal Numbers (Order and Steps)

Ordinal numbers tell us the position or order of something. We use them for dates, floors in a building, or steps in a game.

Sequencing Words (ป.4)

When giving instructions or telling a story, we use these special words to show what happens first and what happens last:

  • First: The beginning.
  • Second: The next step.
  • Then: Used to show the middle steps.
  • Finally: The very last step.

Ranking Numbers (ป.5–ป.6)

These are the words like "1st" or "2nd". Most of them end in -th, but the first three are special!

  • \(1^{st}\) = First
  • \(2^{nd}\) = Second
  • \(3^{rd}\) = Third
  • \(4^{th}\) = Fourth
  • \(5^{th}\) = Fifth (Spelling change: "five" becomes "fifth")
  • \(10^{th}\) = Tenth

Did you know? We use these numbers when we talk about our birthdays! For example: "My birthday is on the tenth of June."

3. Measurements (Size and Age)

In ป.5 and ป.6, we use English to talk about how tall, how old, or how heavy things are. This is very useful when meeting new friends!

Asking and Answering

To find out information, we usually start our questions with "How".

  • Age: "How old are you?"
    Answer: "I am \(11\) years old."
  • Height: "How tall is he?"
    Answer: "He is \(150\) centimeters tall."
  • Quantity: "How many students are there?"
    Answer: "There are \(30\) students."

Common Mistake: When talking about height, remember to use the word "tall" at the end of the sentence.
Correct: "I am \(140\) cm tall."
Incorrect: "I am \(140\) cm long."

Key Takeaway: Use "How old" for age and "How tall" for height.

4. Comparing with Thai

In Thai, we usually put the number after the noun (เช่น สุนัข 2 ตัว). But in English, we usually put the number BEFORE the noun.

  • Thai: สุนัข (dog) + สอง (two)
  • English: Two dogs

Also, in English, if we have more than one (\(1\)) of something, we usually add an "s" to the word (e.g., three apples).

Summary Review

Don't worry if this seems like a lot to remember! Just keep these three points in mind:

  • Numbers: Use "hundred" for big numbers up to \(1,000\).
  • Ordinals: Use First, Second, Third for order and dates.
  • Measurements: Use "How old" and "How tall" to ask about people.

Note: To learn more about telling the time or finding your way around, check out the chapter on "Daily routines, time & directions".