← Back to the lesson: The substitution method

Level 6 – Problem solver

Practice: The substitution method

All the questions sit under each other, like on paper. Where you can tap (signs, yes/no, shapes), tap — do not hunt for a keyboard. Otherwise write the answer and press the tick, or Check all at the bottom. Green = right. Red = not yet. 시작 with ten. When it goes well, add more.

← Back to the explanation Next lesson: The elimination method →