A three-digit number is built from three places: hundreds, tens, and ones.
For example, 365 means three 100s, six 10s, and five 1s, the same as 300 plus 60 plus 5.
The same digit is worth a different amount depending on where it sits, and that is what place value means.
Here you can slide to change the number, watch the hundreds, tens, and ones blocks grow and shrink, and compare two numbers by the length of their bars.
World of Numbers Bigger than 100
🏠 Think of Apartment Numbers!
①301, 502 — many are 3-digit numbers
②Count how many 100s, 10s, 1s
③Knowing place values lets you read big numbers
Place Value Blocks
365
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Decomposing a 3-digit number into hundreds, tens, ones blocks
💡 What is Place Value?
①Hundreds digit → how many 100s
②Tens digit → how many 10s
③Ones digit → how many 1s
Comparing Numbers
425
398
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Comparing two 3-digit numbers with bars
⚖️ How to Compare Sizes
①Compare hundreds digit first
②If equal, compare tens
③If still equal, compare ones
Summary
3-digit Composition
Hundreds × 100 + Tens × 10 + Ones × 1
Multiply each digit by its place value, then sum
3-digit Range
100 ~ 999 (smallest: 100, largest: 999)
3-digit numbers go from 100 to 999
🎯 Remember!
①3-digit numbers: 100 to 999
②Hundreds place has the biggest value
③Compare from highest place down
④Same digit in different places = different value
⑤365 → 3 hundreds, 6 tens, 5 ones
Examples and Unit Test
Example 1
What 3-digit number has 4 in the hundreds, 7 in the tens, and 2 in the ones place?
1
Find each place value: 4×100 = 400, 7×10 = 70, 2×1 = 2.
2
Add them all: 400 + 70 + 2 = 472.
▸ 472
A 3-digit number = (hundreds)×100 + (tens)×10 + (ones)×1.
Example 2
Which is greater, 583 or 561?
1
Compare from the highest place. Both have 5 in the hundreds place.
2
Compare the tens: 8 > 6, so 583 is greater.
▸ 583 (583 > 561)
Compare sizes in order: hundreds → tens → ones.
Unit Test
What number is made of 6 hundreds, 3 tens, and 8 ones?