Return the logical value TRUE for any error type except the #N/A error.

=ISERR(value)

Return the most common value in a data set

=MODE.SNGL(number1, [number2], ...)

Lookup values by column in a horizontal table or range

=HLOOKUP (lookup_value, table_array, row_index_num, [range_lookup])

Sum (add) values in a range that meet a single criteria.

SUMIF(range,criteria,[sum range])

Round a number down to the next multiple

=FLOOR(number, significance)

Search one row or one column (or an array) for a value

(Vector form) =LOOKUP (lookup_value, lookup_vector, [result_vector])

(Array form) =LOOKUP(lookup_value, array)

Count values in a range that meet a single criteria.

COUNTIF(range,criteria)

Remove irregular spacing from either end of or within a text string.

TRIM(text)

Returns a vertical array of the most common values in a data set.

=MODE.MULT(number1, [number2], ...)

Count the number of characters in a string

LEN(text)

Return the logical value TRUE if the cell contains any value that is not text.

=ISNONTEXT(value)

Sum (add) values together.

=SUM(number1,number2,…)

Return the logical value TRUE if the cell contains either a TRUE or FALSE statement.

=ISLOGICAL(value)

Return a random number between 0 and 1

=RAND()

Return the value or reference of specified cell(s)

Array form: =INDEX(array, row_num, [column_num])

Reference form: =INDEX(reference, row_num, [column_num], [area_num])

Extract characters from within a text string.

MID(text, start_num, num_chars), MIDB(text, start_num, num_bytes)