# SAT Math: Arithmetic

## Inclusive Numbers

Tammy will be on vacation from July 3rd through July 18th, inclusive.  How many days will Tammy be on vacation?

A.       15

B.       16

C.       17

D.       20

E.        21

## Knowsys Method

Read the question carefully.  If you miss the word “inclusive,” you will get the wrong answer.

Identify the bottom line.  You need to know how many days.  Make a note in your scratch work that this is the question that you must answer.  D = ?

Assess your options.  You could try to count out the days, but you might make a mistake and there is an easier method.  For inclusive numbers you must include the first day in your count, not simply start counting at the first day.  The fastest way to get the answer is to (1) Subtract the smaller number from the larger number and (2) add 1 to the difference.

Attack the problem.  Once you know what to do, don’t hesitate!  Start plugging in the numbers from your problem.

18 – 3 = 15      (Many students will stop here.  However, you need to include the first day in your count)

15 + 1 = 16

Loop Back.  You solved for the number of days, and you made sure that you have the inclusive number.  You are ready to look down at your answer choices.