There is a shot of the beans in Jack's hand when the monk gives them to him. There are a total of 8 beans. Later, one of the beans goes under the floorboards of Jack's house and that turns into a beanstalk, bringing the bean count down to 7. After climbing the beanstalk, Roderick forces Jack to give him the beans. Jack keeps one of the beans bringing the bean count down to 6. No more beans are used after this until the giants use the beans as a way down to Earth. But when the lead giant takes the beans out of the bag, there are now only 5 beans.