What are some examples of mathematical investigation?

Explain how you can tell 45 is in simplest form? How many hundredths in a whole? What is 1899 in roman numerals? How do you factor 4x squared 8? How far is the earth around? What is 17.5 rounded to the nearest tenth? How many syllables in the word elephant trainer? How do you convert 1.35 mm to fraction? How to calculate mtr to sqmtr? Why isn't zero a prime number? Simplify the square root of 28? What is the center of the circle given by the equation (x - 3)2 (y - 9)2 16? What property says that the way numbers are grouped when added does not make a difference in their sum? What is 664 over 1000 in simplest form? What is the distance from a number and zero on a number line? Which hockey stick is more accurate a straight one or curved? What is a transformation that shrinks or stretches as a figure? How do you solve the equation 4x-5 plus 2x equals 13 plus 9x-21? What number represents XXVIII? Where would you give percentages in everyday life?