Every rod has a place
One rod can only show 0 to 9. To show bigger numbers we use several rods together. Choose a rod to be the ones rod (the unit rod). Every rod to its left is worth ten times more.
| Rod | Thousands | Hundreds | Tens | Ones |
|---|---|---|---|---|
| Value of one earth bead | 1,000 | 100 | 10 | 1 |
Most sorobans have a small dot on the beam every three rods. Use a dotted rod as your unit rod so you can always find your place quickly.
Reading big numbers
Read from left to right, one rod at a time, exactly as you would write the number.
Zero matters. An empty rod in the middle of a number is a zero, just like the 0 in 305. Never skip it.
Setting a number
- Clear the abacus.
- Find your unit rod and count left to the highest place in the number.
- Set each digit from left to right.
Try it yourself
Show 4,062. Use the rightmost rod as the ones rod and remember the zero.
Your abacus shows 0.
Quick check
Type your answers, then check them. Get them all right to complete the lesson automatically.
Practice tips
- Say the place names out loud while setting a number: 'four thousand, zero hundred, six tens, two ones'.
- Always start from the left. That is how we read numbers, and it is how abacus calculation works.