1. NUMBER THEORY

2. Prime Numbers Prime number: only divisible by 1 and itself.
Fundamental Theorem of Arithmetic
How many primes are there?

3. How to find primes from math import sqrt
topnum = int(raw_input("Enter the highest number to check: "))
startnum = 3
print 2
print 3
while startnum < topnum:
for a in range(3,int(sqrt(startnum+1)),2):
if startnum % a ==0:
break;
else:
print startnum
startnum = startnum + 2

4. Divisibility p | q definition. Factoring a number… gcd lcm
modular arithmetic
Applications:
Change
Last digit
Encryption
Calendar computations

5. Congruences Modular equations. Solving congruences…
Diophantine equations