About Lemonmath

What is Lemonmath?

Lemonmath is a free website of clear, step-by-step math lessons for students from grade 1 to grade 12. The lessons follow the topics and the order of Vietnam's national mathematics curriculum (the 2018 general education programme, as used in the Kết nối tri thức textbook series), and every page is available in English and in Tiếng Việt.

What is ready now?

• Grade 10 is complete: nine chapters and 27 lessons, each with worked examples, pictures, key terms and practice problems with full solutions.
• Grades 1–9, 11 and 12 show the roadmap of chapters. Their lessons will be added step by step.

How the lessons are written

Every lesson goes in the same order: a picture or a small example, then the idea in plain words, then the rule, then worked examples, then practice. The text is original; it is not copied from any textbook. The curriculum belongs to the Ministry of Education and Training of Vietnam, and Kết nối tri thức is a textbook series of its publisher. Lemonmath is not affiliated with either.

Your progress

When you press "Mark as complete", the lesson is remembered on your own device only. Nothing is sent to us, and you do not need an account.

Found a mistake?

We would like to know. Please report it here and tell us the lesson and what looks wrong.