Round each value to 1 significant figure then perform the calculation (without a calculator).
Now, (correct to one significant figure); and (again, one significant figure).
Applets: Begin by rounding to one significant figure. Then adjust your answer. Aim for less than 10% error (good), or less than 5% error (excellent!)
Up to 100 multiplied by 100
A little more difficult
Done here – go back to the menu for Unit 1.