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hi guys can any one tell me how computer can multipy internally any number with 3,6,7,9 etc cuz if u multiply any number with two that means number << 1; and number << 2 // means multiplied by 4 number << 3 // means multipled by 8 how i can multipy a number with 3 5 7 etc i hope u have understood my question..

In a modern binary computer, you can only use the integer value and multiply using decimal arthimetic, ie, int i = 3; i = i*3 ;// multiply by three i = i * 5; //multiply by five ...etc There's no bit-shifting trick for these. The "trick" only works for powers of two, because it's in Base-2. Think about the same thing in the decimal system when multiplying by powers of 10...since we use base ten this is as simple as shifting over the digits and adding a zero on the end... 112 << 1 : multiplying by 10 "shifts" digits one time to left (These are pretend - java doesn't have Base-10 shifting, but this is how it would look if it did ) 112 << 1 = 1120 //multiplied by 10 13 << 2 = 1300 //mutliplied by 100 etc. But the answer to your question is "you cant." [ April 18, 2002: Message edited by: Rob Ross ]