Summing can be done manually using the formula n n 1 2. Sum of two consecutive numbers Even number sum of two consecutive numbers whole number. For example in adding a number from 1 through 6 we have 1 6 2 5 and 3 4 which all equals to 6 1 and we know that 6 is the largest number.
Sum of two consecutive numbers Even number sum of two consecutive numbers whole number.
Great so now we can say that the sum of three consecutive numbers is 3 times the middle number. For example in adding a number from 1 through 6 we have 1 6 2 5 and 3 4 which all equals to 6 1 and we know that 6 is the largest number. And the sum of 7 consecutive numbers is 7 times the middle number. 1 2 3 4 5 15.