calculate the answers to the appropriate number of significant figures
In the equation 23.7 x 3.8, the first number has three sig figs and the second has two. When multiplying two numbers with different amounts of sig figs together, the answer will be given the smaller number of sig figs.So, 23.7 x 3.8 is usually 90.06. But the answer has to have two sig figs, like 3.8. So the answer is rounded down to 90. Include the point; otherwise it's only one sig fig, because 0's before the point don't count as sig figs. If you aren't allowed to do that, you can change 90 into 9.0 x 10 to the 1 power. Then the answer will have two sig figs.