Math New Drill (Level 1) : Number sense and theory SNJ00-0705-L1 Sum of consecutive integers

When the sum of seven consecutive integers is 140, find the first number.


Answer
17

Solution
According to 140 / 7 = 20, the mid number is 20 which is the 4th. 


Thus the 1st number is 20 - 3 = 17.