A digit's value depends on its place
The 3 in 3,456 is worth 3,000 but the 3 in 43 is worth 3. Seeing the cubes, flats, rods and ones makes the difference something a child can count.
Place Value & Number Line 🔢
See what each digit is worth with base-ten blocks, and watch ten ones turn into a ten. Then add and take away on a number line, one jump at a time.
Base-ten blocks
Khmer & English words
Number line jumps
Nothing leaves your device
Examples
The number
Result
Good to know
Ten of one make one of the next
Press + on the ones when there are already nine: the ten ones become one ten rod. That is carrying in column addition, and pressing − on an empty column is borrowing.
Jump in tens, then ones
47 + 36 is easier as 47 + 30 = 77, then 77 + 6 = 83. The number line draws each jump so the mental method can be seen, and it works across zero for negative numbers.
Nothing leaves your device
Everything runs in your browser and nothing is saved. The address bar keeps the numbers, so a link opens the same picture for a classmate.
Tool created by
លោក ណាត ប៊ុនឆ័យ · Mr. Nat Bunchhai
Alpha Academy Cambodia
Place value is where number sense begins.
Our tutors build young learners a real feel for numbers — the base for mental maths, column methods and decimals later on.