can someone give me a good explanation of scientific notation. simple but smart. i’m in algebra 1 honors

Tom had a total of $220 and he spent $35 on a basketball ticket . what percent of his money did he have left?

Write the point-slope form of the line passing through (2, -12) and parallel to y=3x.

Sara goes on a slingshot ride in an amusement park. she is strapped into a spherical ball that has a radius 3*10^2 of centimeters. what is the volume of air in the spherical ball? use this formula: volume of a sphere=4/3pi,r^3 , where r is the sphere’s radius.