This chapter contains fun and playful exercises to practise basic operations and arithmetics. Students can learn about number systems and in the Sequences topic there are more challenging tasks, involving proofs.

[url=https://www.geogebra.org/m/ryb8ssex]301 - Multiplication with Heights[/url][br][br][url=https://www.geogebra.org/m/ytvjtbxs]302 - Secret Number[/url][br][br][url=https://www.geogebra.org/m/wg6z6esk]303 - Floor Plan Puzzle[/url][br][br][url=https://www.geogebra.org/m/tmbfagre]304 - Secret Base[/url][br][br][url=https://www.geogebra.org/m/jutkwhu3]305 - Secret Exponent[/url][br][br][url=https://www.geogebra.org/m/yjpznuk5]306 - Binary System[/url][br][br][url=https://www.geogebra.org/m/thzhmhcq]307 - Number System with Base 4[/url][br][br][url=https://www.geogebra.org/m/nqrqhrjj]308 - What Comes Next?[/url][br][br][url=https://www.geogebra.org/m/yfxyaemw]309 - Triangular Square Number[/url][br][br][url=https://www.geogebra.org/m/fgaxv48d]310 - How many Faces[/url][br][br][url=https://www.geogebra.org/m/ee93vfv4]311 - Growing Pine Trees[br][/url]