SOROBAKSpeed Run
Fast calculation

Choose your
speed-training level

4 levels
Level 1
NF

Core calculation

Start with simple steps and build steady speed.

Core calculation level Sorobak owl
Level 2
F5

Friends of 5

Apply the friends-of-five formulas to rapidly displayed numbers.

Friends of 5 level Sorobak owl
Level 3
F10

Friends of 10

Practise the friends-of-ten formulas without losing focus.

Friends of 10 level Sorobak owl
Level 4
MIX

Mixed challenge

Bring all your skills together in one fast challenge.

Mixed challenge level Sorobak owl
Levels: NF: 1 · F5: 2 · F10: 3 · MIX: 4