Potential Paths: Path 1: Use Questionwell because it's specifically designed to create diverse question sets and it can generate questions from various inputs including text, images, audio, or video. This tool also allows the user to select and align their learning objectives with the questions being generated. The questions can be exported to other teaching platforms and the interface is user-friendly. Path 2: Leverage the problem solving and tutoring features of Sizzle. It can guide users through each step of a solution and encourage a deeper understanding of concepts. It has the capability to handle word problems including numbers and algebra, which is aligned with the user's specific request.

Final Narrative: To address your need for open-ended questions related to numbers and algebra for your year 6 students, I recommend using Questionwell. This EdTech product allows educators to generate diverse question sets including open-ended ones. Here's why this tool can address your needs effectively:

1. Customizable Question Generator: Questionwell provides a feature which allows you to generate questions based on various inputs. You can provide the topic (in this case, numbers and algebra), language, and question type (select open-ended) and the tool will generate questions accordingly.
2. Question Bank: This feature helps extract essential questions and aligns them with the learning objectives for the topic. You can also add your own learning objectives to match your lesson plan.
3. Edit and Curate Questions: After you generate questions using Questionwell, you will have the opportunity to select, edit, or duplicate the questions to fit your needs. You can ensure that the open-ended questions generated match your teaching goals.
4. Export Functionality: Once satisfied with the generated questions, these can be exported to various platforms or even printed as a PDF.
5. Free Trial: If budget is a concern, you can try the Pro or Premium plan for free for 14 days.

In addition to generating questions, the user-friendly interface and different pricing plans make Questionwell a compelling choice. Remember, while AI can be helpful, it may require a bit of time to learn how to maximize its features effectively. Always review the generated questions as they may not always perfectly align with specific teaching goals. However, the platform's capacity for customization should make this task manageable and helpful in achieving your educational objectives. Good luck, and happy teaching!