Khushi Abacus learning tutorial big, small and family
Soroban Tutorial - Big Friends & Family
Learn double-digit operations with Big Friends and Family combinations!
Step 1: Introduction
Welcome! We'll cover:
- Big Friends (pairs to 10) for addition and subtraction
- Family Combinations (mixing big and little friends)
- Double-digit practice with tens and units
Step 2: Big Friends Addition
Big Friends: Pairs to 10
9+1, 8+2, 7+3, 6+4, 5+5
Addition: 9=10-1, 8=10-2, 7=10-3, 6=10-4, 5=10-5
Example: 26 + 9
1. Set 26
2. Add 10 (36), subtract 1 (35)
Total = 35
Try adding with big friends!
Step 3: Big Friends Subtraction
Reverse Subtraction: 1=10-9, 2=10-8, 3=10-7, 4=10-6, 5=10-5
Example: 35 - 9
1. Set 35
2. Subtract 10 (25), add 1 (26)
Total = 26
Practice subtracting with big friends!
Step 4: Family Addition
Family Addition (mix big and little friends):
9=10-5+4, 8=10-5+3, 7=10-5+2, 6=10-5+1
Example: 28 + 9
1. Set 28
2. Add 10 (38), subtract 5 (33), add 4 (37)
Total = 37
Try family addition!
Step 5: Family Subtraction
Family Subtraction:
-9=-10+5-4, -8=-10+5-3, -7=-10+5-2, -6=-10+5-1
Example: 37 - 9
1. Set 37
2. Subtract 10 (27), add 5 (32), subtract 4 (28)
Total = 28
Practice family subtraction!
Step 6: Double Digits Practice
Tens: Heaven = 50, Earth = 10 each
Units: Heaven = 5, Earth = 1 each
Example: 45 + 27
1. Set 45
2. Add 27 (tens 2, units 7+5=12, carry 1, total 72)
Total = 72
Practice double-digit operations!
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