To do this manually, you can simply read through the number, keeping a manual tally in your head.
If you are looking for an algorithm to do it for you, here is one method that would work in C, where "number" is the value being tested and "digit" is the digit we're counting:
...
int whole = (int)number;
number -= whole;
tally = 0;
while(whole != 0){
if(whole % 10 digit) tally++;
number -= (int)number;
}
printf("We counted %i digits occurrences of the digit %i\n", tally, digit);
...
find the diagonal method of two digit number and three digit number
To find how many sevens there are from 1 to 1000, we can consider the occurrences of the digit '7' in each digit place (hundreds, tens, and units). In the range from 1 to 999, the digit '7' appears 300 times: 100 times in each of the hundreds, tens, and units places. Including the number 1000, which has no sevens, the total remains 300. Thus, there are 300 occurrences of the digit '7' from 1 to 1000.
To find how many times the digit '7' appears between 1 and 885, we can count the occurrences in each digit place. From 1 to 885, '7' appears in the units place (in numbers like 7, 17, 27, ..., 877), the tens place (in numbers like 70-79, 170-179, ..., 870-879), and the hundreds place (only the number 700-799). In total, there are 88 occurrences of '7' in the units place, 80 occurrences in the tens place, and 100 occurrences in the hundreds place, leading to a total of 268 occurrences of the digit '7'.
To find how many times the digit '9' appears between 1 and 100,000, we can consider each digit place (units, tens, hundreds, thousands, and ten-thousands). Each digit place can independently be '9' in the range of 0 to 99,999, which gives 10,000 occurrences per place. Since there are 5 digit places, the total number of '9's is 5 * 10,000 = 50,000. Thus, there are 50,000 occurrences of the digit '9' between 1 and 100,000.
To find how many times the digit 2 occurs in the tens place from 100 to 1000, we can analyze the range of numbers. The relevant range for the tens place is from 120 to 229, which includes all numbers where the tens digit is 2. This gives us the numbers 120-129 (10 occurrences), 220-229 (10 occurrences), totaling 20 occurrences of the digit 2 in the tens place.
find the diagonal method of two digit number and three digit number
To find how many sevens there are from 1 to 1000, we can consider the occurrences of the digit '7' in each digit place (hundreds, tens, and units). In the range from 1 to 999, the digit '7' appears 300 times: 100 times in each of the hundreds, tens, and units places. Including the number 1000, which has no sevens, the total remains 300. Thus, there are 300 occurrences of the digit '7' from 1 to 1000.
The single-digit that appears most frequently between and including the numbers 1 and 1000 is the digit "1". To see why this is the case, consider the following pattern: Between 1 and 9, there is one occurrence of the digit "1". Between 10 and 99, there are 10 occurrences of the digit "1" in the tens place (10, 11, 12, ..., 19) and 9 occurrences of the digit "1" in the ones place (21, 31, 41, ..., 91), for a total of 19 occurrences. Between 100 and 999, there are 100 occurrences of the digit "1" in the hundreds place (100, 101, 102, ..., 199), 100 occurrences of the digit "1" in the tens place (110, 111, 112, ..., 119, 121, 131, ..., 191, 201, ..., 291, 301, ..., 391, ..., 901, ..., 991) and 9 occurrences of the digit "1" in the ones place (101, 111, 121, ..., 191), for a total of 210 occurrences. Adding up the number of occurrences for each range, we get: 1 + 19 + 210 = 230 Therefore, the digit "1"
there could be a part in it like this: int num, digit; int count [10]; do { digit = num%10; num != 10; ++count[digit]; } while (num);
The last digit is always the estimated digit in a number
"If the units digit and the hundreds digit of the number 513 were reversed..." 315 'find the sum of the original number and the new number." 513+315=828
It is 63.
first you look at the first number tell what that number is then you just find the first digit.
It is 99,899,999.
The units digit of a two digit number exceeds twice the tens digit by 1. Find the number if the sum of its digits is 10.
50
90000 5's are in 450000.