## Basic math functions: log, log10, roman, trunc

#### Excel Function LN

The LN() function is used to determine the natural logarithm of a number.

The natural logarithm of a number is log value with base-e, the value of e being 2.71.

This function is most often used with Engineering problems.

Number | Formula | LN() |

1 | =LN(L4) | 0 |

4 | =LN(L5) | 1.38629436111989 |

45 | =LN(L6) | 3.80666248977032 |

0.4 | =LN(L7) | -0.916290731874155 |

100 | =LN(L8) | 4.60517018598809 |

#### Excel Function LOG

The LOG() function is used to determine the log value of a number to a supplied base value.

This function takes in two parameters; number and base value.

The default base value is 10.

Number | Base | Formula | LOG() |

1 | 2 | =LOG(L16,M16) | 0 |

4 | 3 | =LOG(L17,M17) | 1.26185950714291 |

45 | 4 | =LOG(L18,M18) | 2.74592654816484 |

0.4 | 10 | =LOG(L19,M19) | -0.397940008672038 |

100 | 1 | =LOG(L20,M20) | 0 |

#### Excel Function LOG10

The LOG10() function is used to determine the log value of a number with respect to base 10.

The log value with base 10 is most commonly used in mathematical problems and have extensive applications.

This function takes a single parameter; number.

Number | Formula | LOG10() |

1 | =LOG10(L28) | 0 |

4 | =LOG10(L29) | 0.602059991327962 |

45 | =LOG10(L30) | 1.65321251377534 |

0.4 | =LOG10(L31) | -0.397940008672038 |

100 | =LOG10(L32) | 2 |

#### Excel Function ROMAN

The ROMAN() function is used to convert an Arabic numeral to roman form as text.

This function takes two parameters; numeral and form.

The value of form ranges from 0 to 4 which specifies the conciseness of the conversion in increasing order.

This function has a maximum numeral value limited to 3999.

A negative numeral as parameter will result in an error.

Number | Form | Formula | ROMAN() |

1 | 0 | =ROMAN(L41,M41) | I |

4 | 1 | =ROMAN(L42,M42) | IV |

45 | 2 | =ROMAN(L43,M43) | VL |

3999 | 3 | =ROMAN(L44,M44) | MMMVMIV |

100 | 4 | =ROMAN(L45,M45) | C |

#### Excel Function TRUNC

The TRUNC() function is used to truncate a number to a specified number of decimal places.

This function takes in two parameters; number and number of digits.

A positive value in number of digits specifies the number of digits to the right of the decimal point.

A negative value in number of digits specifies the number of digits to the left of the decimal point.

If omitted, the number of digits is taken as 0.

Number | No. of digits | Formula | TRUNC() |

23.466 | 2 | =TRUNC(L55,M55) | 23.46 |

4 | 1 | =TRUNC(L56,M56) | 4 |

23.098981 | -1 | =TRUNC(L57,M57) | 20 |

-887 | -1 | =TRUNC(L58,M58) | -880 |

0.2344 | 2 | =TRUNC(L59,M59) | 0.23 |