- Arithmetic (Wikipedia)
Arithmetic (from Ancient Greek ἀριθμός (arithmós) ’number’, and τική [τέχνη] (tikḗ [tékhnē]) ‘art, craft’) is an elementary part of mathematics that consists of the study of the properties of the traditional operations on numbers—addition, subtraction, multiplication, division, exponentiation, and extraction of roots. In the 19th century, Italian mathematician Giuseppe Peano formalized arithmetic with his Peano axioms, which are highly important to the field of mathematical logic today.
- Rhizome (Wikipedia)
In botany and dendrology, a rhizome (/ˈraɪzoʊm/; from Ancient Greek ῥίζωμα (rhízōma) ‘mass of roots’, from ῥιζόω (rhizóō) ‘cause to strike root’) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow horizontally. The rhizome also retains the ability to allow new shoots to grow upwards.