Algebra is a branch of mathematics which involves solving equations. Algebra is the study of mathematical symbols and the rules for manipulating these symbols.

Lining up numbers by place value is a mathematical method which involves aligning the digits of two or more more numbers according to their place value.

Numeration, a fundamental concept in mathematics, is the process of representing numbers using symbols or digits. One most common system is the decimal system.

Pi is a character in the roman alphabet ( Ï€ ). In mathematics it is used to represent the ratio of a circle's circumference to it's diameter ( C / d ).

In mathematics, the Base 10 system uses ten digits, 0 to 9, to represent numbers and is the foundation for advanced mathematical concepts such as algebra.