How do you clear the error -- model tn33 20 11 2p90 used by x tx4k tx4 is undefined?

What is 149 grams converted to kilos? What is 5 trillion divided by 308 million? What is one times ten to the twentieth power? How many times does 2 go into 99 with out going over? What is 41.25 divided by 3? What is the ratio15 to 12? How many times is the word new used in the Bible? What is the mean of 34 41 39 26? What is the estimated product of 5 x 9301? What does m c m means in Roman numerals? What is value of 170000000000? Is (0-2) a solution of 2x-5y10? How long is a ranch in centimeters? Does a parallelogram have edges? How many lengths of straw would you need to build a pentagonal based pyramid? What is 8 to the 2nd power? What does 22 cm look like? Is the sum of a positive and negative integer always negative? Is 36 divisible? What between 4 and 5 in number lines?