Unique Selling Points

Multiple Difficulties

Our Lehrer Lämpel Apps offer multiple levels of difficulty. There are exercices that are rather easy, medium ones, and also challenging exercices.

Direct feedback

Apps give direct feedback. If configured accordingly, learners see immediately whether their steps is correct or incorrect.

Intelligent diagnosis

Our Lehrer Lämpel App for fractions is capable of identifying typical errors, and generating appropriate remedial feedback.

Step-by-step solutions

Our Lehrer Lämpel Apps never give away the entire solution, but lead learners step-by-step towards the solutions - by giving context-sensitive hints.

Unlimited number of exercices

Our Lehrer Lämpel Apps have no fixed pool of exercises. In fact, there are unlimited exercises! For basic arithmetic, there are also predefined work-sheets. Or define your own math problem!

Solve problems by racing against time.

Our Apps NumberPyramids and NumberWheels allow learners to train their math skills under time pressure. Can you solve a number wheel in record time?

Our Apps

Multi-Column Addition

One of the first algorithm, pupils learn at school. The App allows learners to deal with 5-digit numbers.

  • $ 1.99

Multi-Column Subtraction

Supports two basic subtraction algorithms: the decomposition method as well as the equals addition method.

  • $ 1.99


Worksheets, self-defined or randomized exercises. Step-by-step help.

  • $ 1.99


Worksheets, self-defined or randomized exercises. Step-by-step help.

  • $ 1.99

Number Pyramids

A true classic. Small, medium and large pyramids (and numbers). Choice of number positioning.

  • $ 0.99

Number Wheels

Another classic. Trains all four basic skills. Race against the time! Can you beat your record?

  • $ 0.99

Number Squares

Not always easy to solve. May require some combinatorial/logical thinking.

  • $ 0.99


For fifth graders. Adding and subtracting fractions the correct way (smallest multiple, any multiple?).

  • $ 0.99

Multi-column addition (blob tasks)

Free variant of our addition app. Same features, plus blobs!

  • FREE