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Last updated on August 18, 2025
10001 in binary is a representation of the decimal number 17, as the binary system uses only two digits, 0 and 1, to represent numbers. This system is widely used in computer systems. In this topic, we are going to learn about binary representation of 17.
The process of converting 17 from decimal to binary involves dividing the number 17 by 2. Here, it is divided by 2 because the binary number system uses only two digits (0 and 1). The quotient becomes the dividend in the next step, and the process continues until the quotient becomes 0.
This is a commonly used method to convert 17 to binary. In the last step, the remainder is noted down from bottom to top to get the converted value.
For example, the remainders noted down after dividing 17 by 2 until the quotient is 0 are written as 10001. Remember, the remainders here have been written in reverse order.
In the table shown below, the first column shows the binary digits (1 and 0) as 10001.
The second column represents the place values of each digit, and the third column is the value calculation, where the binary digits are multiplied by their corresponding place values.
The results of the third column can be added to cross-check if 10001 in binary is indeed 17 in the decimal number system.
17 can be converted easily from decimal to binary. The methods mentioned below will help us convert the number. Let’s see how it is done.
Expansion Method: Let us see the step-by-step process of converting 17 using the expansion method.
Step 1 - Figure out the place values: In the binary system, each place value is a power of 2. Therefore, in the first step, we will ascertain the powers of 2.
20 = 1
21 = 2
22 = 4
23 = 8
24 = 16 Since 16 is less than 17, we stop at 24 = 16.
Step 2 - Identify the largest power of 2: In the previous step, we stopped at 24 = 16. This is because we have to identify the largest power of 2, which is less than or equal to the given number, 17. Since 24 is the number we are looking for, write 1 in the 24 place. Now the value of 24, which is 16, is subtracted from 17. 17 - 16 = 1.
Step 3 - Identify the next largest power of 2: In this step, we need to find the largest power of 2 that fits into the result of the previous step, 1. The next largest power of 2 that is less than or equal to 1 is 20. Now, we have to write 1 in the 20 place. And then subtract 1 from 1. 1 - 1 = 0. We need to stop the process here since the remainder is 0.
Step 4 - Identify the unused place values: In step 2 and step 3, we wrote 1 in the 24 and 20 places. Now, we can just write 0s in the remaining places, which are 21, 22, and 23. Now, by substituting the values, we get: 1 in the 24 place 0 in the 23 place 0 in the 22 place 0 in the 21 place 1 in the 20 place
Step 5 - Write the values in reverse order: We now write the numbers upside down to represent 17 in binary. Therefore, 10001 is 17 in binary.
Grouping Method: In this method, we divide the number 17 by 2. Let us see the step-by-step conversion.
Step 1 - Divide the given number 17 by 2. 17 / 2 = 8. Here, 8 is the quotient and 1 is the remainder.
Step 2 - Divide the previous quotient (8) by 2. 8 / 2 = 4. Here, the quotient is 4 and the remainder is 0.
Step 3 - Repeat the previous step. 4 / 2 = 2. Now, the quotient is 2, and 0 is the remainder.
Step 4 - Repeat the previous step. 2 / 2 = 1. Here, the quotient is 1, and 0 is the remainder.
Step 5 - Repeat the previous step. 1 / 2 = 0. Here, the remainder is 1. And we stop the division here because the quotient is 0.
Step 6 - Write down the remainders from bottom to top. Therefore, 17 (decimal) = 10001 (binary).
There are certain rules to follow when converting any number to binary. Some of them are mentioned below:
This is one of the most commonly used rules to convert any number to binary. The place value method is the same as the expansion method, where we need to find the largest power of 2. Let’s see a brief step-by-step explanation to understand the first rule. Find the largest power of 2 less than or equal to 17. Since the answer is 24, write 1 next to this power of 2. Subtract the value (16) from 17. So, 17 - 16 = 1. Find the largest power of 2 less than or equal to 1. The answer is 20. So, write 1 next to this power. Now, 1 - 1 = 0. Since there is no remainder, we can write 0 next to the remaining powers (21, 22, and 23). Final conversion will be 10001.
The division by 2 method is the same as the grouping method. A brief step-by-step explanation is given below for better understanding. First, 17 is divided by 2 to get 8 as the quotient and 1 as the remainder. Now, 8 is divided by 2. Here, we will get 4 as the quotient and 0 as the remainder. Dividing 4 by 2, we get 2 as the quotient and 0 as the remainder. Dividing 2 by 2, we get 1 as the quotient and 0 as the remainder. Divide 1 by 2 to get 1 as the remainder and 0 as the quotient. We stop the division once the quotient becomes 0. Now, we write the remainders upside down to get the binary equivalent of 17, 10001.
This rule also involves breaking the number into powers of 2. Identify the powers of 2 and write them down in decreasing order, i.e., 24, 23, 22, 21, and 20. Find the largest power that fits into 17. Repeat the process and allocate 1s and 0s to the suitable powers of 2. Combine the digits (0 and 1) to get the binary result.
The limitation of the binary system is that only 0s and 1s can be used to represent numbers. The system doesn’t use any other digits other than 0 and 1. This is a base 2 number system, where the binary places represent powers of 2. So, every digit is either a 0 or a 1. To convert 17, we use 0s for 21, 22, and 23, and 1s for 24 and 20.
Learning a few tips and tricks is a great way to solve any mathematical problems easily. Let us take a look at some tips and tricks for binary numbers up to 17.
Memorize to speed up conversions: We can memorize the binary forms for numbers 1 to 17. 1 → 1, 2 → 10, 3 → 11, 4 → 100, 5 → 101, 6 → 110, 7 → 111, 8 → 1000, 9 → 1001, 10 → 1010, 11 → 1011, 12 → 1100, 13 → 1101, 14 → 1110, 15 → 1111, 16 → 10000, 17 → 10001.
Recognize the patterns: There is a peculiar pattern when converting numbers from decimal to binary. 1 → 1 1 + 1 = 2 → 10 2 + 2 = 4 → 100 4 + 4 = 8 → 1000 8 + 8 = 16 → 10000 16 + 1 = 17 → 10001
Even and odd rule: Whenever a number is even, its binary form will end in 0. For example, 10 is even, and its binary form is 1010. Here, the binary of 10 ends in 0. If the number is odd, then its binary equivalent will end in 1. For example, the binary of 17 (an odd number) is 10001. As you can see, the last digit here is 1.
Cross-verify the answers: Once the conversion is done, we can cross-verify the answers by converting the number back to the decimal form. This will eliminate any unforeseen errors in conversion.
Practice by using tables: Writing the decimal numbers and their binary equivalents on a table will help us remember the conversions.
Here, let us take a look at some of the most commonly made mistakes while converting numbers to binary.
Convert 17 from decimal to binary using the place value method.
10001
24 is the largest power of 2, which is less than or equal to 17.
So place 1 next to 24.
Subtracting 16 from 17, we get 1.
So the next largest power would be 20.
So place another 1 next to 20.
Now, subtracting 1 from 1, we get 0.
Now, we just place 0s in the remaining powers of 2, which are 21, 22, and 23.
By using this method, we can find the binary form of 17.
Convert 17 from decimal to binary using the division by 2 method.
10001
Divide 17 by 2.
In the next step, the quotient becomes the new dividend.
Continue the process until the quotient becomes 0.
Now, write the remainders upside down to get the final result.
Convert 17 to binary using the representation method.
10001
Break the number 17 into powers of 2 and find the largest powers of 2.
We get 24. So 1 is placed next to 24. Next, 17 - 16 = 1.
Now, the largest power of 2 is 20.
Once again, 1 is placed next to 20.
Now, 1 - 1 = 0.
After getting 0, fill in with zeros for unused powers of 2.
By following this method, we get the binary value of 17 as 10001.
How is 17 written in decimal, octal, and binary form?
Decimal form - 17 Octal - 21 Binary - 10001
The decimal system is also called the base 10 system.
In this system, 17 is written as 17 only.
We have already seen how 17 is written as 10001 in binary.
So, let us focus on the octal system, which is base 8.
To convert 17 to octal, we need to divide 17 by 8.
So 17 / 8 = 2 with 1 as the remainder.
In the next step, divide the quotient from the previous step (2) by 8.
So 2 / 8 = 0 with 2 as the remainder. The division process stops here because the quotient is now 0.
Here, 1 and 2 are the remainders, and they have to be written in reverse order.
So, 21 is the octal equivalent of 17.
Express 17 - 8 in binary.
1001
17 - 8 = 9 So, we need to write 9 in binary.
Start by dividing 9 by 2.
We get 4 as the quotient and 1 as the remainder.
Next, divide 4 by 2. Now we get 2 as the quotient and 0 as the remainder.
Divide 2 by 2 to get 1 as the quotient and 0 as the remainder.
Divide 1 by 2 to get 0 as the quotient and 1 as the remainder.
Now write the remainders from bottom to top to get 1001 (binary of 9).
Hiralee Lalitkumar Makwana has almost two years of teaching experience. She is a number ninja as she loves numbers. Her interest in numbers can be seen in the way she cracks math puzzles and hidden patterns.
: She loves to read number jokes and games.