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Add fast!

Problem #56
Deadline to submit the solution: December 31st , 2001

Think of a fast way to add numbers from 1 to 100.

1+2+3+4+5+6+7+8+9+10+.........+95+96+97+98+99+100=

Q1. What is the final sum?
Q2. Explain your method. (In the Solution field)

 

Solutions:

 

Janey from Canada
Grade: 6 Age: 10
Solution:
Q1: 5050

First I added a 0 to the beginning of the line of numbers, then I noticed that the opposite sides of the numberline equal 100 (eg 0+100, 1+99, 2+98 etc)I knew that before you get to the middle "50" there will be 50 hundreds, so then I add 50 to 5000 and get 5050
About me:
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Eddie from U.S.A
Grade: 3 Age: 8
Solution:
Q1: 5050
Q2: Answer in the explain category

You add 100 and 1 and 99 + 2 and so on and each one equals 101 and their are 50 pairs so 101 + 101 50 times equals 5050 .
About me: I am now getting into playing and less smarter but I don't want to be a rocket scientist when I grow up I want to be a piano violen composer .
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Zach from Willow Hill PA USA
Grade: 5 Age: 10
Solution:
Q1: 5,050

We added 99 and 1, 98 and so on until we got to 50 but can't double 50. So we came out with we came out with 4 thousands one 950 and one 100 We then added all the numbers to get 5,050.
About me: Klinton is in 5th grade with his 2 best friends. They are smart and the one's that helped him to answer this problem. Myles likes to go to sim theme park.com and visit other people's parks. Zach is a sporty guy and has a great teacher. That teacher is Miss Miley We are all friends
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Sam from Pittsburgh PA
Grade: 4 Age: 9
Solution:
Q1: 5050

1+99,2+98,3+97...... would equal 100. If you do that to 49,you would get 49 one hundreds. Then you would have a 50 and a 100 left. Then 49 times 100+50+100 equals 5050.
About me: About me I loooove cars I especialy like sports cars like Lamborghini Diabio SV. Also I like reading very much
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Vickshaana from Canada
Grade: 3 Age: 8
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Mubina from USA
Grade: 2 Age: 7
Solution:
Q1: 5050

Simple, In numbers 1 to 49 add numbers 99 to 51. All pairs will add up to 100.There are 49 such pairs. Than add numbers 100 and 50 to your total of pairs to get your final answer.
About me: I am in grade 2 and I love solving math puzzles.
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