Excel Everest’s online training.
Trusted online excel training courses
SUM function: Use this function to add the values in cells.
IF function: Use this function to return one value if a condition is true and another value if it’s false.
LOOKUP function: Use this function when you need to look in a single row or column and find a value from the same position in a second row or column.
VLOOKUP function: Use this function when you need to find things in a table or a range by row. 
DAYS function: Use this function to return the number of days between two dates.
FIND, FINDB functions: FIND and FINDB locate one text string within a second text string. They return the number of the starting position of the first text string from the first character of the second text string.
INDEX function: Use this function to return a value or the reference to a value from within a table or range.
MATCH function: Use this function to search for an item in a range of cells, and then return the relative position of that item in the range. 
CHOOSE function: Use this function to select one of up to 254 values based on the index number.
DATE function: Use this function to return the sequential serial number that represents a particular date. For example, you might have a worksheet that contains dates in a format that Excel does not recognize, such as YYYYMMDD. Use the DATEDIF function to calculate the number of days, months, or years between two dates
