Q: What is the sum of counting numbers from 1 to 20?

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The sum of the first six counting numbers (1-6) is 19.

1, 2, 3, and 5

I assume you mean the first three "counting" (ordinal) numbers, which are 1, 2, and 3. The sum is therefore 1 + 4 + 9 = 14.

There are (not counting 1) three square numbers between 1 and 20.

The sum of the squares of the first 20 natural numbers 1 to 20 is 2,870.

Related questions

The sum of the first six counting numbers (1-6) is 19.

The sum of the first 10 counting numbers (1-10) is 51.

The sum of the first 100 counting numbers (1-100) is 5,001.

1+1+1+1+1+=5 * * * * * The question did not ask for the sum of the first counting number five times! The sum of the first 5 counting numbers is 1+2+3+4+5 = 15. Such sums are known as triangular numbers.

The sum of the first 500 counting numbers (1-500) is 125,001.

20*(20+1)/2 = 210 If you want to see how this works, or even the beauty in numbers, you can do so in MS Excel. In cell A1 put "=ROW()" B1: "=SUM(A$1:A1)" C1: "B1/A1". Then, select and copy those three cells. Paste the content in any number of rows down in those three columns. Be sure to note the following patterns: Every 20 numbers, the one's digit repeats itself in the sum column (B column), The sum of the first 10 numbers is 55, the first 100 is 5050, 1000 is 500500.

1 and 3

105

1, 2, 3, and 5

I assume you mean the first three "counting" (ordinal) numbers, which are 1, 2, and 3. The sum is therefore 1 + 4 + 9 = 14.

20 and 1. 20 + 1 = 21 20 - 1 = 19

1,2,3,4 1+2+3+4=10 4 times 3 times 2 times 1 =24 24 counting numbers