About sekibun.com

What is sekibun.com?

sekibun.com is a free site that generates math practice problems and shows each one with a detailed solution. It covers arithmetic drills, middle-school math, high-school math (the Japanese courses Math I, A, II, B, C and III) and university calculus, linear algebra and differential equations, each topic at three levels (basic, standard and advanced).

It is built for everyone from people who want to solve a few problems in spare moments, to students preparing for exams, to teachers making handouts, tests and problem books. Our aim is a place where new problems never run out and every problem comes with an answer and a solution.

Features

• Problem generator: choose your grade and term, or a course, topic and level, and press the button for a new problem with different numbers. Word problems are built from scenario templates with changing numbers.
• Clean answers: prefer problems whose answers are integers or simple fractions (Loose, Up to fractions or Integers only).
• Answer checking and math keyboard: enter expressions, solutions of equations, inequalities, coordinates, matrices and more to see if they are correct; on phones you can use the on-screen math keyboard. Construction and proof problems show a model answer.
• Worksheets and PDF: mix topics and difficulty levels into an A4 worksheet. The page count and layout are automatic, with name fields, answer pages, double-sided printing and an answer QR code.
• Online answers and automatic grading: students answer online from the QR code and save an answer file; teachers grade many answer files at once on the Grading page.
• My page: see the history of your worksheets. With a free account you can keep it across devices and organize it in folders.
• Japanese version: switch with "JA" at the top right.

How problems are made and checked

Problems are built from templates for each topic, filled in with randomly chosen numbers and expressions. The same program computes the answer and every step of the solution.

To keep them correct, every update of the site generates large numbers of problems in every topic and automatically checks the answers by an independent method (substitution, counting, numerical computation and so on), checks that typing the correct answer is accepted, and checks that all formulas render.

If you still find a mistake or something unclear, please tell us through the contact form with the problem ID (No.). Automatic grading is not guaranteed to be accurate, so we recommend that teachers and students double-check the results.

Using the problems

Besides personal study, teachers and tutors may freely reuse generated problems, including figures, answers and solutions, in handouts, tests and problem books without contacting us. Please check the content yourself before use. See the Terms of use for details.

Grades on this site follow the Japanese curriculum: Grades 7–9 are middle school and Grades 10–12 are high school.

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