numbers and algebraic expressions
logic, sets, intervals
function and its properties
limits of sequences and functions
derivative and integral of functions
elements of statistics
Round number to 2 decimal places: 3.528, 3.523, 3.525, 12.7898, 4.29999, 2/7, square root of 3, pi. Digit on second decimal place increase by 1, if third decimal digit is greater or equal as 5.