பத்துகள் மற்றும் ஒன்றுகள்
Tens and Ones
The abacus has many rods. The rod on the right is the ones place. The rod next to it is the tens place. Learn how two rods work together to show bigger numbers.
Let's Learn
What you will learn today
Understand that each rod on the abacus has a different place value — ones, tens, and more.
So far you have used ONE rod. But what about 10? Or 23? For bigger numbers, we use MORE rods. Each rod has a job, and the job depends on which rod it is. This is called place value.
Quick recap
You can now show any number from 0 to 9 on one rod. But for 10, 11, 12... we need a second rod. Each rod has a different job. Let's find out what they are.
Place value — the big idea
In the number 23, the 3 means 3 ones. The 2 means 2 tens (twenty). Same digits, different meanings because of position. The abacus shows this perfectly — each rod is a position.
The ones rod (ஒன்றுகள் தண்டு)
The RIGHTMOST rod is the ones rod. Numbers on this rod mean exactly what they say: 1 bead = 1, 3 beads = 3. This is the rod you have been using all along!
The tens rod (பத்துகள் தண்டு)
The rod just to the LEFT of the ones rod is the tens rod. Numbers on this rod are multiplied by 10. So 1 bead on the tens rod = 10. 2 beads = 20. 3 beads = 30.
📐 Showing 10 — one ten, zero ones
Left rod (tens): 1 lower bead up = 10. Right rod (ones): clear = 0. Total: 10 + 0 = 10.
📐 Showing 23 — two tens and three ones
Tens rod: 2 lower beads up = 20. Ones rod: 3 lower beads up = 3. Total: 20 + 3 = 23.
📐 Showing 35 — three tens and five ones
Tens rod: 3 lower beads up = 30. Ones rod: upper bead down = 5. Total: 30 + 5 = 35.
How to read a two-rod number
Always read left to right. Tens rod value × 10, plus ones rod value × 1. Just like how we write and read numbers.
Reading rods backwards
A very common mistake: reading the ones rod first (right to left). Always read LEFT to RIGHT — tens first, then ones. The number 23 has 2 on the tens rod (left) and 3 on the ones rod (right).
Try showing 12
Show the number 12 on the two-rod abacus.
🎯 Goal: Show the number 12
Now try 31
Show the number 31 on the two-rod abacus.
🎯 Goal: Show the number 31
Challenge Round
Show 39 — the big test
Show the number 39 on the two-rod abacus. This one needs 3 beads on the tens rod AND the full combination on the ones rod. Think carefully!
🎯 Goal: Show the number 39
You understand place value now! Each rod has a role: ones rod (×1) and tens rod (×10). In the next lesson, you will use both rods together to build all numbers from 10 to 20.
↪ Next: Building Numbers 10 to 20
Key Points
முக்கிய குறிப்புகள்
- ✓The RIGHTMOST rod = ones place
- ✓The rod to its LEFT = tens place
- ✓Each rod follows the same bead rules
- ✓1 bead on tens rod = 10
- ✓Read left to right: tens digit first, ones digit second
Lesson Materialsபாட வளங்கள்
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Glossary
சொல் அகராதி
Ones place
ஒன்றுகள் இடம்
Tens place
பத்துகள் இடம்
Place value
இட மதிப்பு
Two-digit number
இரு இலக்க எண்
Rightmost rod
மிகவும் வலது தண்டு
Practice Activities
Quizவினாடி வினா
Answer each question to check your understanding.
ஒன்றுகள் இடம் எந்த தண்டு?
Which rod shows the ones place?
Match the Termsபொருத்துக
Click a term on the left, then click its matching definition on the right.
Click a term, then click its matching definition.
Terms
Definitions
Fill in the Blanksஇடைவெளி நிரப்புக
Type the missing word and press Check or Enter.
Type the missing word and click Check.