Increase and Decrease

  I learned how to decrease and increase by percentages   The way that you decrease is the same as increase with one extra step, subtracting. 

• The first step is subtracting the numbers.  For example, 60 - 18 = 42.  
• Than after that you divide 42 by the original number 60 divided by 42.  
• Since this is impossible we add a zero 420 divided by 60 = 70. That is increase. 
• To decrease you do 100 - 70 = 30 that is decrease.  This answer stopped early but you usually need to add zeros for a little longer.