Based on your search query for "graphs", I recommend using Symbolab. This tool is a comprehensive mathematical tool that includes a graphing calculator feature. This feature allows you to graph equations, functions, and inequalities, which can be a great aid in visualizing these concepts for your students.

Additionally, Symbolab provides step-by-step solutions to a wide array of mathematical problems. This can be particularly useful in teaching, as it allows you to demonstrate the process of solving complex mathematical problems, helping students understand the logic behind each step.

The platform also offers a practice feature with thousands of problems and quizzes to help students improve their math skills. Plus, with the digital notebook feature, users can keep track of math problems and notes.

Symbolab is available as a website and a mobile app, with the app allowing users to type in or snap a picture of a math problem and get step-by-step solutions. This could be a convenient feature for students who want to practice or review on the go.

The tool offers both a free version and a premium subscription. The free version provides access to the solver with limited step-by-step solutions, while the premium version offers ad-free usage, unlimited step-by-step solutions, and additional practice problems. The pricing for the premium subscription is $2.49 per week, $6.99 per month, or $29.99 per year.