Here, dear geek, are three nifty mind widgets to make mates want you and peers want to be you.

**Multiply up to 20x20**

1. For example, take 17x13

2. Place the larger number on top, in your head

3. Imagine a box, encompassing the 17 and the 3

4. Add these to make 20

5. Add a zero to this, to make it 200

6. Multiply the 7 and the 3 to get 21

7. Add this to 200 to get the answer: 221

**Multiply any two-digit number by 11**

1. For example, take 79

2. Add a space between the two digits, making 7___9

3. Add 7 and 9 to get 16

4. Put 16 into the space (remember to carry the tens digit!)

5. The answer is 869

**Multiply by 9 on your fingers**

1. Lay your spread fingers on a table in front of you

2. To multiply by 4, fold down the fourth finger from the left

3. Now read your fingers: there are three to the left of the fold and six to the rightâ€”this makes 36.

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