What is the half of2+2 =? if i say 3 (100 % fail)

Hello, this is the tech of the world. In this series I am going to show some tips and trick in mathematics So I am starting by this equation and problem:

1. What is half of 2+2 =?

If you say 3 that is corrects.Its why?        🤔 

 Because I say that half of 2+2.So 

1/2 x 2+2=1+2            

                =3

2. What is the sum of a to 10? means 1+2+3+.........................+100..................infiny

Yes, I have a formula if the difference is 1.
Like: 2-1=1
28-27=1


that types f equation is solved by this formula:
                                      sum   =n(n+1)/2
whether n= total number(1-10=10 number)
Let us see some examples :
1,2,3,4,5,6,7,8,9,10
If you use calculator then the sum of these numbers is 55.
But some times you have not calculator
Then use this formula ;

sum of 1-10=(n+1)n/2
                   =(10+1)10/2
                   =11*5
                   =55 ans//

so bye-bye friends? I give you a logical and mathematics-related question.If you solve that then you have high mathematics skills. If you don't know then comment us.


3. When I was 5, my sister was double my age, now I am 10, how old is my sister?