A unique application for practicing addition and subtraction

Peculiarities:
- No ready-made answers - stimulates mental processes
- Select the difficulty of examples: counting to ten, passing through ten, adding and subtracting two-digit and single-digit numbers, as well as two-digit numbers up to 100
- Selection of questions for training, taking into account previous answers
- Timing to respond, taking into account the complexity of the example
- Assessment for work, according to which you can see progress in learning
- Laconic, minimalistic interface
- Takes up little space on the phone