இரண்டு விதிகளும் சேர்ந்து
Both Rules Together
Some problems need the 5-rule. Some need the 10-rule. Some need both! Learn to spot which rule applies and apply it confidently in the right order.
Let's Learn
What you will learn today
Recognise which rule (5-rule, 10-rule, or both) each problem needs, and apply the right one without hesitation.
Quick rule recap
5-rule addition: upper bead down (+5), complement lower beads down. 5-rule subtraction: upper bead up (−5), complement lower beads up. 10-rule addition: add 1 to tens, subtract complement from ones. 10-rule subtraction: remove 1 from tens, add complement to ones. All four rules are now in your toolkit.
Now comes the skill that separates good from great: choosing the right rule quickly. Some problems need the 5-rule. Some need the 10-rule. Some need both rules in sequence. The key is to notice what the problem is asking before you move any beads.
சரியான விதியை தேர்வு செய்வதே திறமை.
Decision tree: which rule?
Ask yourself these questions in order:
- Question 1: Does the result of this step fit on the current rod? If YES → direct move (no rule needed). If NO → continue.
- Question 2: Am I staying on the ones rod? If YES → 5-rule. If NO (crossing to tens) → 10-rule.
- After using a rule, check again: does the new state require another rule for the next step?
📐 Example: 4 + 3 = ?
Ones shows 4. Add 3.
- 1Does 4+3=7 fit on ones rod? Yes (7 ≤ 9).
- 2But can I push 3 lower beads up from 4? I have 4 beads up, space for 0 more below and upper bead is up. I need the 5-rule for the ones rod.
- 35-rule: upper bead down (+5), 5-complement of 3 (=2) lower beads down (−2). Ones: 4+5−2=7 ✓
📐 Example: 5 + 8 = ?
Ones shows 5. Add 8.
- 1Does 5+8=13 fit on ones? No (13 > 9). This is a 10-rule problem.
- 210-rule: add 1 to tens, subtract 10-complement of 8 (=2) from ones: 5−2=3.
- 3Tens:1, ones:3 → 13 ✓
📐 Example that needs both: 3 + 8 = ?
Ones shows 3. Add 8.
- 1Does 3+8=11 fit on ones? No. Use 10-rule.
- 210-rule: add 1 to tens, subtract 10-complement of 8 (=2) from ones: 3−2=1.
- 3Tens:1, ones:1. But wait — 3−2=1, and ones shows 3 lower beads. Subtract 2: 3−2=1. Does this need a 5-rule? No, 3 has 3 lower beads showing and we subtract 2 directly.
- 4Final: Tens:1, Ones:1 → 11 ✓
The real secret: take it one step at a time
Advanced students sometimes try to jump ahead and do everything at once. Don't. Do each move separately, check the result, then decide the next move. Speed comes from consistent practice, not from rushing.
Challenge Round
Challenge: which rule does 6 + 4 need?
Ones shows 6. You need to add 4. Does the result fit on ones? Which rule do you need?
Rule selection: (1) Does it fit? → direct. (2) Staying on one rod? → 5-rule. (3) Crossing rods? → 10-rule. (4) Both? → Apply them in sequence, one step at a time.
↪ Next: Speed Drill — practise all rules until they become automatic reflexes.
Key Points
முக்கிய குறிப்புகள்
- ✓First ask: can I do this directly? If yes, do it. If no, use a rule.
- ✓If staying on one rod: 5-rule
- ✓If crossing rod boundaries: 10-rule
- ✓Apply rules one step at a time — don't rush
Glossary
சொல் அகராதி
Mixed problems
கலப்பு கேள்விகள்
Rule selection
விதி தேர்வு
Sequence
வரிசை
Direct move
நேரடி நகர்வு
Practice Activities
Speed Drill · விரைவு பயிற்சி
Mixed Rules Drill
கலப்பு விதி பயிற்சி
Quizவினாடி வினா
Answer each question to check your understanding.
You need to calculate 4 + 4. The result is 8. Which rule do you use?
Fill in the Blanksஇடைவெளி நிரப்புக
Type the missing word and press Check or Enter.
Type the missing word and click Check.