Subtracting 9s shortcut

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Subtracting 9s shortcut

Add the digits of the larger number

• 10 - 9 = 1 + 0 = 1
• 11 - 9 = 1 + 1 = 2
• 12 - 9 = 1 + 2 = 3
• 13 - 9 = 1 + 3 = 4
• 14 - 9 = 1 + 4= 5
• 15 - 9=. 1 + 5 = 6
• 16 - 9 = 1 + 6= 7
• 17 - 9= 1 + 7 = 8
• 18 - 9 = 1 + 8 = 9
• 19 - 9 = 1 + 9 = 10