Here is an easy tool where you can put the date and get the day of the week:
Day of the Week Calculator
1ís & 2's complement are methods for representing signed numbers in binary number system.
They are very important in computer science as we use them today in every computer or smartphone.
Here is are tools that convert from decimal to 1ís & 2's complement and vice versa:
1's Complement Calculator
2's Complement Calculator
Gray code is a binary numeral system where two successive values differ in only one bit. It is also known as the reflected binary code.
Here is an online tool that converts a binary number to gray code number and vise versa:
Gray Code Converter
Shannon entropy allows to estimate the average minimum number of bits needed to encode a string of characters based on the alphabet size and the frequency of the characters.
Use this calculator to calculate it:
Shannon Entropy Calculator
Bitwise operations operates on the bit level of a number.
They may perform faster then operations on the byte level, for example bitwise operations are much faster then equivalent multiplication or division operations.
Check this calculator here:
Linear Regression is an approach for modeling the straight line relationship between variables by using a linear equation to observed data.
The linear regression line is represented by the formula Y = A + BX, where X is the explanatory variable and Y is the dependent variable. A is the intercept of the line and B is its slope.
Here is the calculator:
Linear Regression Calculator