Problem-posing is an effective learning strategy for the comprehension of problem structures. We designed and developed a learning environment for problem-posing and undertook practical experiments with first- and second-grade students at elementary school. The system included arithmetic word problems using one-step addition, subtraction, or multiplication. The results suggested that the learning environment is effective in helping students to comprehend these problem structures. This led us to design and develop a learning environment for posing one-step multiplication or division word problems, with a view to teach learners how to differentiate between multiplication and division. It was found that the learning environment could be used practically in elementary schools.