Answer:
k-n+1
51
21
Step-by-step explanation:
How many numbers are written from n to k
Lets look at a smaller example with real number
Lets go from 3 to 8
3 4 5 6 7 8
There are 6 numbers
We take 8 -3 = 5, but we include the number 3 so we add it back in +1
5+1 =6
Lets look at a larger example
2 to 11
2,3,4,5,6,7,8,9,10,11
There are 10 numbers
11-2 =9 but we have to add back in the first number
9+1 =10
Now we are going from n to k
k-n = k-n, but we have to add back in the first number
k-n+1
How many numbers from 50 to 100
100-50 +1 = 51
How many numbers from 0 to 20
20-0+1 =21
