Addition
Subtraction
Multiplication
???
100

5 + 9

 14


100

27 - 5

22

100

7 x 6

42

100

What's my name?

What is Theodore or Theo? (Teddy is negative a million points)

200

70 + 23

93

200

46 - 21

25

200

14 x 19

266

200

 What's a motivation for studying mental math?

Judges decision. 

300

64 + 29

93


300

94 - 76

18

300

2 x 43

86

300

Describe the trick for multiplying numbers between 10 and 20. You can use 14 x 16 as an example. 

Judges decision. 

400

144 + 56


200


400

24 - 60

-36

400

11 x 94

1034

400

What is the compliment of 43?

57

500

987 + 456


1443

500

912-456

456

500

22 x 67

1474

500

What is the name of the "Mathemagician" who inspired the ideas in this talk?

Dr. Arthur Benjamin