(1) -Adding consecutive numbers:--
Add the smallest number in the group to the largest number in the group,multiply the result by the amount of numbers int the group and divide the resulting product by 2
example:- 35+36+37+38+39+40+41+43+44=?
(35+44)*10/2=395
(2)-Shortcut Method (Mentally) To find compliment of 100 i.e.the difference between 100 and the given number. This will help calculation faster and useful for competitive exams like IBPS Bank PO,SSC CGL,IAS,SBI PO,RBI Exam,CBI,CPO Exam,RRB And campus recruitment exams.
(a) First subtract the unit digit of number to be subtracted from 100 mentally. The result will be unit digit of result.Then subtract 10's digit from 9 and place it at the position of 10's digit into result .Now result will be answer.This is easy to mentally calculate.
(2)-Shortcut Method (Mentally) To find compliment of 100 i.e.the difference between 100 and the given number. This will help calculation faster and useful for competitive exams like IBPS Bank PO,SSC CGL,IAS,SBI PO,RBI Exam,CBI,CPO Exam,RRB And campus recruitment exams.
(a) First subtract the unit digit of number to be subtracted from 100 mentally. The result will be unit digit of result.Then subtract 10's digit from 9 and place it at the position of 10's digit into result .Now result will be answer.This is easy to mentally calculate.
