1) The development of mathematics, including number systems and arithmetic, was driven by practical needs in areas like trade, taxation, and military affairs. Place value systems like the Hindu-Arabic numerals made complex calculations possible.
2) Early algebra developed out of solving practical problems involving lengths and areas. Techniques like extracting roots and solving quadratic equations were applied to problems in areas like right triangles and bone setting.
3) Geometry originated from practical construction needs but was formalized by Euclid into a deductive system. It influenced fields like art and tiling patterns. Relating geometric concepts to algebraic formulas helped develop modern algebra.