"When something does not fit in the space given, it does not vanish — it overflows, and changes what came before."

When Eleven Overflows

When you multiply a two-digit number by 11 and the digits add up to more than 9, the trick still works — but the extra digit carries left, just like in regular addition.

85 \times 11

Step 1: Add the digits: 8 + 5 = 13

Step 2: The 3 goes between the digits

Step 3: The 1 carries left — 8 becomes 9

Result: 935

+1 8

13 3

78 \times 11

Step 1: Add the digits: 7 + 8 = 15

Step 2: The 5 goes between the digits

Step 3: The 1 carries left — 7 becomes 8

Result: 858

+1 7

15 5

Now you try. Remember to carry when the digits add past nine.

67 \times 11 =

94 \times 11 =

56 \times 11 =

88 \times 11 =

Insight When the digits overflow past nine, the extra carries left — just like in addition. The trick still works, it just ripples forward.

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