SPI.transfer( fontArray [ highByte(yourInt) ] ); // swap these 2 around if needed
SPI.transfer( fontArray [ lowByte(yourInt) ] );
If the value contained in youint is a normal "int" and desired values
to be displayed on the LEDs are decimal, then this will not work.
For example if the value of yourint is 12
then highByte would be 0 and lowByte would be 12 or 0xc
If the desire is have one led show '1' and the other show '2' for this value,
then the value of yourInt must first be converted to BCD before you
grab the hight and low bytes.