Binary, Octal, & Hexadecimal Number Systems and Their Conversions

Decimal to Binary

Decimal numbers are converted to binary by repeated division of the given number by 2, and recording the remainder. The remainder is read from the bottom to the top. 

For example:

If the number is 43, the remainder obtained on dividing it by 2 every time will give the result 110101, which inverted is 101011, therefore the answer will be: 4310 = 101011

Decimal to Octal

Decimals are converted to octal numbers by repeated divisions of the given number by 8. 

An example would be:

If the number 473 is divided by 8 repeatedly it will give the remainder 1, 3, and 7, on the first, second, and third division respectively. 

Therefore the result will be:

47310 = 7318

Decimal to Hexadecimal

Decimal numbers can be converted to hexadecimal by repeated division of the number by 16 while recording the remainder.

Reference

Binary, Octal, & Hexadecimal Number Systems and Their Conversions