Task 8. "Put eight of yours in front of you. If you give me five of yours, how many will you have left?"
Immediately after completion of this task, the following question was posed. "If you give me three blocks of your eight, many will you have left?" The purpose of this second question was to determine how many of the children could give a correct response without hesitating or using the blocks if the part initially known became the missing part.
Task 9. "Put fourteen of your blocks in front of you. If you give me six blocks, how many blocks will you have left?" This, too, was closely followed by "If you give me eight blocks from your fourteen blocks, how many blocks will be left?"
At this stage in the interview, most children were increasingly confident of their observations when they were able to use materials. Responses were faster, the use of blocks was more rapid, and there was less hesitation about volunteering a response or attempting to find a solution.