21 Decimal in Binary

Let's convert the decimal number 21 to binary without using a calculator:

Step 1: Divide by 2

Start by dividing 21 by 2:

21 ÷ 2 = 10 (Quotient) with a remainder of 1

Step 2: Divide the Quotient

Now, divide the quotient (10) by 2:

10 ÷ 2 = 5 (Quotient) with a remainder of 0

Step 3: Divide the Quotient

Now, divide the quotient (5) by 2:

5 ÷ 2 = 2 (Quotient) with a remainder of 1

Step 4: Divide the Quotient

Now, divide the quotient (2) by 2:

2 ÷ 2 = 1 (Quotient) with a remainder of 0

Step 5: Final actions

The Quotient is less than 2 (1), so we will transfer it to the beginning of the number as a reminder.

Step 6: Write the Remainders in Reverse Order

Now, write down the remainders obtained in reverse order:

10101

So, the binary representation of the decimal number 21 is 10101.

Decimal To Binary Converter

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