Calculator -- Time, GCD, LCM

Contains a simple standard calculator and add, subtract, multiply and divide units of time is a time calculator .
1. year, day, hour, minute, and second can be calculated by the calculator
2. support mix units of time. Ex.10h5m5s+5m1h = 11hr 10min 5sec
3. support converted button to convert into units of another time style.
4. You can use a standard calculator including square root and reciprocal.

※ To use this calculator, first you should know :
Entering a time (such as 07:08:09 + 5 hours) to enter an input to the following sequence.
07:08:09 To enter , type the following:
1. Number 7 and h input
2. Number 8 and m input
3. Number 9 and s input
4. input + add button
5. Number 5 and h input
6. input to = equal button
The result will display 12h 8m 9s on screen.
You can press Convert button to convert another time style.

Recent changes:
1.add 'read me'
2.support number format

Last version as below,
1. (year, day, hour, minute, and second) can be calculated by the calculator.
2. Contains a simple standard calculator and add, subtract, multiply and divide units of time is a time calculator.
3. Change background color when you press three-dots option button in top-right corner.
4. Report supports divisors, prime, prime factorization, factors and multiples.
5. Factorial (n!) supports real number and negative number.