Someone help me ASAP

Jackson is teaching the decimal number system. he wants his students to know how to expand numbers by powers of 10. which is the correct order in which digits are assigned values in the decimal number system?

Knowing that the central portion of link bd has a uniform cross sectional area of 800 mm2 , determine the magnitude of the load p for which the normal stress in link bd is 50 mpa. (hint: link bd is a two-force member.) ans: p = 62.7 kn

Ac++an of of pi. in , pi is by : pi = 4 – 4/3 + 4/5 – 4/7 + 4/9 - 4/11 + 4/13 - 4/15 + 4/17 . ., to pi (9 ). , if 5 to pi,be as : pi = 4 - 4/3 + 4/5 - 4/7 + 4/9 = 4 – 1. + 0.8 - 0. + 0. = 3.. atoofbe to pi?