Anybody can learn to count fast if he knows the secret of following trick.
Ask your friend to write any five-figure (五位) number on the blackboard. Then you write your five-figure number under it. You choose your figures so that each one with the figure above it will  make nine.
Tell your friend to put a third five-figure number under your number. Then you write a fourth number in the same way. After he has written the fifth number, you draw a line under it and quickly write the sum.(总和). You may even write it from left to right..
How do you do it ? You take away two from the fifth number and put two in front of your answer. Is it interesting?
If your friend’s number is 76815, your number must be_____________________.

A．23184

B．54613

C．93184

D．99999

How many six-figure numbers are there on the blackboard at last?

A．Three

B．One

C．Five

D．Four

If the fifth number is 49834, the sum will be_____________________.

A．249834

B．298344

C．298342

D．249832