- Sauk River (Washington) (Wikipedia)
The Sauk River is a tributary of the Skagit River, approximately 45 miles (72 km) long, in northwestern Washington in the United States. It drains an area of the high Cascade Range in the watershed of Puget Sound north of Seattle. The river is a popular destination for fly fishing. It is a National Wild and Scenic River
- 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.