Answer:
I am a mini solar powered computer.
found at the back of the book.
Sometimes I am white, sometimes I am dark. Most people love me. What am I?
There are four of us but it seems like everyone loves spades the most.
I work when I play and play when I work. What am I?
It flows out of the soil, It burns you if it boils, And holds us in its coils, More valuable than gold, As black as it is old.