THE DOUBLING RULE NUMBER ONE

This is sometimes called the 1-1-1 rule because you are dealing with words of:

one syllable - one vowel - ending in one consonant;  hop
Double the final consonant hopping
but do not double x y w

(The reason for the rule is that the vowel in the ending cannot get back past a double consonant to make the vowel long (as it does in hoping meaning wishing for or in jumping where there is already a double consonant).
Remember: I was hoping for a sunny day and hopping up and down with with impatience.