Materials: calculator
Showing off your Skills:
1. Tell your friend to write a 3digit number on a scrap of paper.
Every number must not be the same.
2. Tell your friend to repeat step 1. The same rules apply.
3. Last number. This is the number you notice of thiers.
4. Now comes your part. Write a number so when you add up thier first number and yours it equals 999.
5. Write one more so that the second number of thiers and your second number equals 999 again.
6 Wait a bit. Then give the sum of the 3 numbers they wrote down and the two you did.
7. Why does this trick work?
Look at our trials:
Number one: 693 349 809 306 +650 2807 
867 204 140 132 +795 2138 
Number three: 912 786 987 087 +213 2985

2. Tell your friend to write the number backwards underneath the first number.
3. Have the friend use the calculator to subtract the lesser number from the greater number.
4. Then say "Tell me the digit in the hundreds place or the digit in the ones place. You also have to tell me if it is in the ones or hundreds place.
5. Wait a bit then give the answer.
Check out these trials:
934 439 934

567 765 765

809 908 908

Materials: calculator and a calendar
Showing off your skills:
Give your friend the calendar.
1. Tell your friend to chose a month and to secretly circle, highlight, or whatever you want to do to any three date that are next to each other in a row or a column.
2. Now tell your friend to add all three dates together. Tell him/her to give you the calculator showing the sum on the screen.
3. Ask if the dates circled are in the row or column.
4. Wait a bit then give the numbers in the problem.
Trials:
SUNDAY  MONDAY  TUESDAY  WEDNES.  THURSDAY  FRIDAY  SATURDAY 
1  2  3  4  5  
6  7  8  9  10  11  12 
13  14  15  16  17  18  19 
20  21  22  23  24  25  26 
27  28  29  30  31 
Orange: "column"=45 8, 15, 22
Blue: "row"=54
17, 18, 19