1 Prime sieve 11

2 The Arithmetic Triangle 56

3 Catalan numbers and mountain patterns 59

4 Pentagon and the Golden Rectangle 62

5 Stirling's Triangle 63

6 Dual partitions of 17 66

7 Central portion of the number line near O 70

8 The evens and the squares paired with the natural numbers 86

9 Cantor's Diagonal Argument 89

10 Rationals separate any given positions on the number line 93

11 Evolution of Cantor's Middle Third Set to the 4th level 95

12 Lattice points on the line of a linear equation 99

13 Addition of complex numbers by adding directed line segments 111

14 The position of a complex number in polar coordinates 113

15 Multiplication by i rotates a complex number by a right angle 117