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Last updated on August 26, 2025
313 in binary is written as 100111001 because the binary system uses only two digits 0 and 1 to represent numbers. This number system is used widely in computer systems. In this topic, we are going to learn about 313 in binary systems.
The process of converting 313 from decimal to binary involves dividing the number 313 by 2. Here, it is getting divided by 2 because the binary number system uses only 2 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 313 to binary. In the last step, the remainder is noted down bottom side up, and that becomes the converted value.
For example, the remainders noted down after dividing 313 by 2 until getting 0 as the quotient is 100111001. Remember, the remainders here have been written upside down.
In the table shown below, the first column shows the binary digits (1 and 0) as 313.
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 100111001 in binary is indeed 313 in the decimal number system.
313 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 313 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
25 = 32
26 = 64
27 = 128
28 = 256 Since 256 is less than 313, we stop at 28 = 256.
Step 2 - Identify the largest power of 2: In the previous step, we stopped at 28 = 256. This is because in this step, we have to identify the largest power of 2, which is less than or equal to the given number, 313. Since 28 is the number we are looking for, write 1 in the 28 place. Now the value of 28, which is 256, is subtracted from 313. 313 - 256 = 57.
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, 57. So, the next largest power of 2 is 25, which is less than or equal to 57. Now, we have to write 1 in the 25 places. And then subtract 32 from 57. 57 - 32 = 25.
Step 4 - Continue the process for remaining value: Repeat the process for 25. The next largest power of 2 is 24, which is 16. Write 1 in the 24 place and subtract 16 from 25. 25 - 16 = 9.
Step 5 - Continue for 9: The next largest power of 2 for 9 is 23, which is 8. Write 1 in the 23 place and subtract 8 from 9. 9 - 8 = 1.
Step 6 - Continue for 1: The next largest power of 2 for 1 is 2^0, which is 1. Write 1 in the 20 place and subtract 1 from 1. 1 - 1 = 0.
Step 7 - Fill in 0s for unused place values: In steps 2 to 6, we wrote 1 in the 28, 25, 24, 23, and 20 places. Now, we can just write 0s in the remaining places, which are 27, 26, 22, and 21. By substituting the values, we get: 1 in the 28 place 0 in the 27 place 0 in the 26 place 1 in the 25 place 1 in the 24 place 1 in the 23 place 0 in the 22 place 0 in the 21 place 1 in the 20 place Therefore, 100111001 is 313 in binary.
Grouping Method: In this method, we divide the number 313 by 2. Let us see the step-by-step conversion.
Step 1 - Divide the given number 313 by 2. 313 / 2 = 156. Here, 156 is the quotient and 1 is the remainder.
Step 2 - Divide the previous quotient (156) by 2. 156 / 2 = 78. Here, the quotient is 78 and the remainder is 0.
Step 3 - Repeat the previous step. 78 / 2 = 39. Now, the quotient is 39, and 0 is the remainder.
Step 4 - Repeat the previous step. 39 / 2 = 19. Here, the remainder is 1.
Step 5 - Repeat the previous step. 19 / 2 = 9. Here, the remainder is 1.
Step 6 - Repeat the previous step. 9 / 2 = 4. Here, the remainder is 1.
Step 7 - Repeat the previous step. 4 / 2 = 2. Here, the remainder is 0.
Step 8 - Repeat the previous step. 2 / 2 = 1. Here, the remainder is 0.
Step 9 - Repeat the previous step. 1 / 2 = 0. Here, the remainder is 1. And we stop the division here because the quotient is 0.
Step 10 - Write down the remainders from bottom to top. Therefore, 313 (decimal) = 100111001 (binary).
There are certain rules to follow when converting any number to binary. Some of them are mentioned below:
Rule 1: Place Value Method
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 313. Since the answer is 28, write 1 next to this power of 2. Subtract the value (256) from 313. So, 313 - 256 = 57. Find the largest power of 2 less than or equal to 57. The answer is 25. So, write 1 next to this power. Now, 57 - 32 = 25. Find the largest power of 2 less than or equal to 25. The answer is 24. So, write 1 next to this power. Now, 25 - 16 = 9. Find the largest power of 2 less than or equal to 9. The answer is 23. So, write 1 next to this power. Now, 9 - 8 = 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 (27, 26, 22, and 21). Final conversion will be 100111001.
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, 313 is divided by 2 to get 156 as the quotient and 1 as the remainder. Now, 156 is divided by 2. Here, we will get 78 as the quotient and 0 as the remainder. Dividing 78 by 2, we get 39 as the quotient and 0 as the remainder. Divide 39 by 2 to get 19 as the quotient and 1 as the remainder. Divide 19 by 2 to get 9 as the quotient and 1 as the remainder. Divide 9 by 2 to get 4 as the quotient and 1 as the remainder. Divide 4 by 2 to 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. We stop the division once the quotient becomes 0. Now, we write the remainders upside down to get the binary equivalent of 313, 100111001.
This rule also involves breaking of the number into powers of 2. Identify the powers of 2 and write it down in decreasing order i.e., 28, 27, 26, 25, 24, 23, 22, 21, and 20. Find the largest power that fits into 313. 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 313, we use 1s for 28, 25, 24, 23, and 20, and 0s for 27, 26, 22, and 21.
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 313.
Memorize to speed up conversions: We can memorize the binary forms for numbers 1 to 10. 1 → 1, 2 → 10, 3 → 11, 4 → 100, 5 → 101, 6 → 110, 7 → 111, 8 → 1000, 9 → 1001, 10 → 1010.
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 + 16 = 32 → 100000…and so on. This is also called the double and add rule.
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 313 from decimal to binary using the place value method.
100111001
28 is the largest power of 2, which is less than or equal to 313.
So place 1 next to 28.
Subtracting 256 from 313, we get 57.
So the next largest power would be 25.
So place another 1 next to 25.
Subtracting 32 from 57, we get 25.
The next largest power of 2 is 24.
So place 1 next to 24.
Subtracting 16 from 25, we get 9.
The next largest power of 2 is 23.
So place 1 next to 23.
Subtracting 8 from 9, we get 1.
Finally, place 1 next to 20.
By using this method, we can find the binary form of 313.
Convert 313 from decimal to binary using the division by 2 method.
100111001
Divide 313 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 313 to binary using the representation method.
100111001
Break the number 313 into powers of 2 and find the largest powers of 2.
We get 28. So 1 is placed next to 28.
Next, 313 - 256 = 57.
Now, the largest power of 2 is 25.
Once again, 1 is placed next to 25.
Continuing the process helps get the binary value of 313 as 100111001.
How is 313 written in decimal, octal, and binary form?
Decimal form - 313 Octal - 471 Binary - 100111001
The decimal system is also called the base 10 system.
In this system, 313 is written as 313 only.
We have already seen how 313 is written as 100111001 in binary.
So, let us focus on the octal system, which is base 8.
To convert 313 to octal, we need to divide 313 by 8.
So 313 / 8 = 39 with 1 as the remainder.
In the next step, divide the quotient from the previous step (39) by 8.
So 39 / 8 = 4 with 7 as the remainder.
Lastly, 4 / 8 = 0 with 4 as the remainder.
The division process stops here because the quotient is now 0.
Here, 4, 7, and 1 are the remainders, and they have to be written in reverse order.
So, 471 is the octal equivalent of 313.
Express 313 - 5 in binary.
100110100
313 - 5 = 308 So, we need to write 308 in binary.
Start by dividing 308 by 2.
We get 154 as the quotient and 0 as the remainder.
Next, divide 154 by 2.
Now we get 77 as the quotient and 0 as the remainder.
Divide 77 by 2 to get 38 as the quotient and 1 as the remainder.
Continue this process until the quotient becomes 0.
Now write the remainders from bottom to top to get 100110100 (binary of 308).
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.