Posted by Hannah on Saturday, August 10, 2013 at 2:13am.
If I add all the numbers from 1100 what do I get? This question has been confusing me for a while...

Math  Sue, Saturday, August 10, 2013 at 2:19am
901

Math  Anonymous, Saturday, August 10, 2013 at 2:26am
you get 5050

Math  Aman, Saturday, August 10, 2013 at 2:28am
5050

Math  Jai, Saturday, August 10, 2013 at 2:30am
The formula for calculating the sum of consecutive number is
S = n*(a1 + an) / 2
where
n = number of terms
a1 = first number
an = last number
Since it is from 1 to 100, n = 100. Substituting,
S = 100*(1+100)/2
S = 5050
Hope this helps~ :)

Math  Steve, Saturday, August 10, 2013 at 4:20am
You can also do it quickly as Gauss discovered when he was a child.
Consider all the numbers as if written in two lines.
150 ascending
10051 descending
adding the two numbers that are in the same positions, each pair makes 101. There are 50 such pairs, so the sum is 5050.
Answer This Question
Related Questions
 math please  Add or subtract exponents? I don't know when to add or subtract it...
 Algebra  Hello all! I had a quick homework question: I have to prove that the ...
 PreAlgebra  What is the process of Scientific Notation? It gets confusing ...
 Math  I'm sorry it's been a while since I've been on Jishka. how are you guys? ...
 math  4 numbers are drawn at random from 10 tiles numbered 09. what are the ...
 Math  Help! How do I complete these magic squares! They're taking me FOREVER! ...
 Math riddle  Im less then 125 and greater then 120 add 100 to me and all my ...
 math help please!!!  In this question how do you know when to add or subtract...
 math  list all numbers from the given set {9,4/5,0,0.25,/3,9.2,/100} that are...
 math  In this question do I add, subtract, or multiply the exponents? 100^12...
More Related Questions