If the 7th grade science classes have raised 50% of the total needed to meet their goal of $750.00, they have raised 750.00 * 0.50 = $375.00.
If they have raised one-third of the amount of their goal of $750.00, they have raised 750.00 / 3 = ${data-answer}lt;<750/3=250.00>>250.00.
Since the classes have raised a total of $375.00 + $250.00 = $625.00, they need to raise an additional 750.00 - 625.00 = ${data-answer}lt;<750-625=125.00>>125.00 to reach their goal of $750.00.
