Multiplying by 11: The Eleven Times Table Patterns

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What is the pattern for multiplying $11$ by a single-digit number (like $1, 2, ..., 9$)?

You just write the digit twice. For example, $11 \times 4 = 44$.

$$ 11 \times 1 = ? $$

$$ 11 \times 1 = 11 $$

$$ 11 \times 2 = ? $$

$$ 11 \times 2 = 22 $$

$$ 11 \times 5 = ? $$

$$ 11 \times 5 = 55 $$

$$ 11 \times 7 = ? $$

$$ 11 \times 7 = 77 $$

$$ 11 \times 9 = ? $$

$$ 11 \times 9 = 99 $$

$$ 11 \times 10 = ? $$

$$ 11 \times 10 = 110 $$ (Just add a zero, like with any number multiplied by 10.)

$$ 11 \times 11 = ? $$

$$ 11 \times 11 = 121 $$

$$ 11 \times 12 = ? $$

$$ 11 \times 12 = 132 $$

How can you figure out $11 \times 12$ easily?

You can think of it as $(10 \times 12) + (1 \times 12)$. That's $120 + 12$, which equals $132$.