A 176 additional

While I think that Duke or URL has provided the correct RAW answer with regards to rounding, I feel it's notable to provide as evidence a monster statblock. The epic monster Genius Loci has a movement speed of 5 ft. and an associated -15 penalty to Jump checks (total mod +5 with a Strength of 50 and no ranks or other bonuses). This indicates that it may be the intention to halve the bonus/penalty when dealing with an increase or decrease of only 5 feet.