The sum of the digits 0-9 : 0 + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9, which equals 45.

Next, the sum of the digits of the numbers 10-19 : \(\left(10\cdot1\right)+\left(0+1+...+9\right)\)

Then, the sum of the digits of the numbers 20-29 : \(\left(10\cdot2\right)+\left(0+1+2+...+9\right)\)

So we have this expression :

(0 + 1 +...+ 9) - The numbers 0-9

\(10\cdot1+\left(0+1+...+9\right)\)- The numbers 10-19

\(10\cdot2+\left(0+1+...+9\right)\)- The numbers 20-29

\(10\cdot3+\left(0+1+...+9\right)\)- The numbers 30-39

\(10\cdot4+\left(0+1+...+9\right)\) -The numbers 40-49

\(10\cdot5+\left(0+1+...+9\right)\) -The numbers 50-59

\(10\cdot6+\left(0+1+...+9\right)\) -The numbers 60-69

\(10\cdot7+\left(0+1+...+9\right)\) -The numbers 70-79

\(10\cdot8+\left(0+1+...+9\right)\) -The numbers 80-89

\(10\cdot9+\left(0+1+...+9\right)\)  - The numbers 90-99.

Calculate all of these expressions we have the sum of the digits from 1-99 is 900.

So the sum of the digits from 1 - 100 is 900 + 0 + 0 + 1 = 901.

Answer : 901.

We have:

(100 - 1) : 1 + 1 = 100 (numbers)

=> (100 + 1) x 100 : 2 = 5050

Answer : 5050

The number of digits from 1-100 is:

(100-1):1+1=100(number)

the sum of the digits from  is:

(100+1)x100:2= 5050

Answer: 5050

Oh! Sorry because I didn't read the question carefully. Thank ForOver.

Hey guy (LeQuocTranAnh), the question asked the sum of the digits not numbers.

I think you've wrong in reading thread :<

The numbers in the sum is: 100-1+1 = 100 (numbers)

So the sum is: \(100\left(100+1\right):2=5050\)

So the answer is: 5050 (ForOver is wrong)