Factor Tree and Prime Notation

FACTOR TREE

For example 68 and 108:

     

      68                                                   108

    2     34                                           2       54

         2      17                                            2    27
                                                                     3    9

                                                                         3   3       must divide with prime number

                                                                        

This helps with finding the HCF and LCM. 

The factors which are the same are multiplied with each other. {2x2} The highest common factor is 4.

To find the LCM, you must multiply the highest powers of each number. Therefore the lowest common multiple is 2x2x3x3x3x17. This is 1836.

This is what you do when they ask you to answer questions in index notation. Instead of writing 2x2 for example, you must write 2 (with indices) to the power of 2.