Place value abacus online
One spike for each place: ones on the right, then tens, hundreds and thousands. Put beads on a spike to show how many of that place there are. It is the abacus in many 1st and 2nd grade math books.
Tap + or the spike to add a bead, − to take one off
0 = 0
How it works
Each spike holds up to nine beads. Three beads on the hundreds spike, four on the tens spike and two on the ones spike show 342: three hundreds, four tens and two ones. Written in expanded form, that is 300 + 40 + 2, which the tool shows under the abacus as you go.
A spike with no beads is a zero in that place. In 507 the tens spike is empty, and seeing the empty spike in the middle is the clearest way for a child to understand why the zero must be written.
Ideas for practice
- Show a number: the tool picks a number; your child puts the right beads on each spike.
- Read the abacus: the beads are set; your child writes the number.
- Ten makes one: put nine beads on the ones spike, then ask what happens with one more: ten ones become one ten, so the ones spike empties and one bead goes on the tens spike.
Which grade?
Tens and ones are a big part of 1st grade math (understanding that the two digits of a number stand for tens and ones), and hundreds come in 2nd grade. In the UK this work sits in Years 1 to 3. The same idea, one rod per place, is how the soroban works, so the place value abacus is a good bridge to the abacus course. Printable place value sheets are on the worksheets page, and classroom ideas are on the page for teachers.