Rule of three practical learn

Rule of 3 calculator learning exercises Voice 10 languages

-With voice (optional, no sound if uncheck). Learn easyly rule of 3

- 10 languages. English, Spanish, , Italian, Russian, Hindi, French, German, Portuguese ,Chinese, Arabian.

-Teaches simple rule of three. With voice and tests.

-Rule of three direct and inverse

-Revises the test with or without voice.

-On top of learning rule of 3 the student can learn some foreign languages.

-Both written and spoken.

-Realistic voice, almost human.

-Also incorporates calculator.