10
Just try it out!
Adding consecutive odd numbers
1, 3, 5, 7, 9, 11 and just keep adding 2 until you get to 99.
6 9 11 23
This equals to the even number 12.
10
Just try it out!
Adding consecutive odd numbers
1 + 3 + 5 + 7 + 9 + 11 = 36
1+3+5+7+9+11 = 36
2 + 3 = 5 2 + 5 = 7 2+ 11 = 13 2 + 41 = 43 The numbers only work with 2 because adding odd numbers together equals an even number. 2 is the only even prime number and thus adding any other prime numbers together will not equal a prime.
1, 3, 5, 7, 9, 11 and just keep adding 2 until you get to 99.
1, 3, 5, 7, 9, 11 and keep adding two until you get to 999.
1, 3, 5, 7, 9, 11 and just keep adding 2 until you get to 99.
You can work this out by realizing that the sum of the first x odd numbers is equal to x2.Consider the following examples:The first three odd numbers: 1 + 3 + 5 = 9The first five odd numbers: 1 + 3 + 5 + 7 + 9 = 25The first ten odd numbers: 1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 + 19 = 100In each case, the number of odds you're adding together is the square root of their sum. This means that the first 1500 consecutive odd numbers have a sum of 15002, which equals 2250000, or two and a quarter million.
1, 3, 5, 7, 9, 11 and just keep adding 2 until you get to 99.