Select the level of problem you'd like to solve (Easier, Easy, or Harder). The table will be reset leaving one or more values blank. Blank fields will be highlighted in red. Based on the value of one or more other properties shown in the table, calculate the missing value(s). Each answer will be evaluated one at a time as either correct or incorrect. If you enter a correct value the field color will change from red to blue. You may select another problem set up at any time.