Numbers up to 100,000 - Grade 3 Math, Term 1

1. Reading and Writing Hindu–Arabic Numbers, Thai Numbers, and Numbers in Words

Each number can be written in several ways, for example:

5 4, 0 2 7

• Hindu–arabic numerals: 5 4, 0 2 7
• Thai numerals: ๕ ๔, ๐ ๒ ๗
• In words: Fifty four thousand twenty seven (no need to read the zero)

2. Place, Value of Digits in Each Place, and Writing Numbers in Expanded Form

Example

Put 5 4, 0 2 7 into the place value table as follows:

Each digit has a different digit value. For example:

The digit 4 in 54,027 is in the thousands place → its value is 4,000

We can write 54,027 in expanded form as: $$ \begin{align} 54{,}027 & = 50{,}000 + 4{,}000 + 0 + 20 + 7 \\ & = 50{,}000 + 4{,}000 + 20 + 7 \quad \text{(no need to write the 0)} \end{align} $$

3. Comparing and Ordering Numbers in Elementary School Math

Use symbols (a crocodile wanting to eat the bigger number):

• > greater than, e.g. $7>3$
• < less than, e.g. $4<8$
• = equal to

When comparing numbers, start from the leftmost digit because it is the highest place value.

4. Number Patterns that Increase or Decrease by the Same Amount

A pattern is a sequence of numbers that changes in a repeated way. At this level, we will “add” or “subtract” the same number repeatedly.

✨ Example:
Start with 2 and add 3 each time → 2, 5, 8, 11, 14, ... (each number increases by 3)

✨ Another example:
Start with 50 and subtract 10 each time → 50, 40, 30, 20, ... (each number decreases by 10)