Tye 7447 and 7448 are BCD-to-seven-segment display drivers. They are not fully decoded (saving transistors was important in the ~1960s), so invalid inputs provide oddball outputs rather than blanking or showing some semblance of a hex character. Valid BCD inputs are 0x00 .. 0x09, and 0x0A to 0x0F are invalid. If you intend to show the result in hex format you would need to make or find a HEX-to-seven-segment display driver or decoder. If you intend to show the result in decimal digits (from 0 to 225 in this case) you would need to interpose a logic circuit between the multiplier output and the BCD display drivers to convert 8 bit binary to 3 digit BCD. I suspect the object of your assignment is the latter. One such method is the 'add 6' algorithm.