The numbers from 0-9 are here represented as they appear in digital clocks:

     
    __         __     __            __     __   __     __    __ 
   |  |   |    __|    __|   |__|   |__    |__     |   |__|  |__| 
   |__|   |   |__     __|      |    __|   |__|    |   |__|   __|

An example of a multiplication (a 2-digit number by an 1-digit number) unidentified because some "LEDs" failed and are "off" (they had to be "on") is shown at left, and the correct one is shown at right (the alignment is perfect):

                                            __     __
                     |                      __|   |__|
           |                               |__    |__|
                                                   __
                                                  |__| 
            x     |                         x     |__|
   -------------------              ------------------
            __                       __     __    
       |    __       |               __|    __|   |__|   
    |      |         |              |__    |__       |

Can you "turn on" the failing "LEDs" in the 3-digit by 3-digit multiplication below?

                                          __     __
                                  |                |
                                  |      |     
                            x      __            
                                     |    __      
                                            |   |__
                            ------------------------
                                                 
                                  |  |      |   
                            __|             |   |  | 
                            __            
                       |   |         |    __|
                    |              __    
                                   
                |      |          |
                |    __    |  |    __ 
             ---------------------------------------
                                                 __
                |    __       |    __    |  |   
                |   |         |    __            __

(In reply to confused by Monica)

I looked at this expecting this to be a simple situation of 0-9 being associated with 10 symbols; I have found 17!

In the Chatterbox, Desiree contended that you need to work from the 6 digits which are the multiplier and multiplicand. 

From this, I note a change in the tense [pcbouhid once admitted some problems with verbs - auxiliary(?)] which I originally overlooked.  In the introduction the LEDs had "failed", but for the problem, they were "failing", meaning that there might be inconsistencies of display.

Also I had not carefully noted the two 8's in the example are displayed differently, as are the two 2's in the answer line!

Consider the layout of the digits for 2 and 3; no matter how they failed, there is only one layout to get a 6, but there is one position that they cannot light. 

More clearly perhaps, if I multiply 9 and 3, I expect the lower left vertical to be blank; should it be lit, then the number is not '7' and my two digits are incorrect.

With time on my side I'll give those ideas a test.

Edited on August 10, 2005, 4:10 am

Posted by brianjn on 2005-08-10 04:00:45