In the lab manual for this lab, you will find the page with Ruler A, a picture of a pencil, a picture of a pen, and Ruler B (from top to bottom). Ruler B is offset 0.50 cm to the left (probably from a margin re-set in Word before it was saved as a pdf). Part of what you are to do in this labis to use Ruler A and Ruler B to measure the pen (just line things up on the page, no need to cut things out). The instructions walk you through using the pencil as an example. So, when you do the pen and use Ruler B, record the value at the tip of the pen (right-hand side), and then subtract 0.50 cm. Please show this work on your data sheet. Rank the following from smallest to largest: 1 mm, 1 m, 1 cm 1L, 1 ml, 1 ul 1 kg, 1 mg, 18 Estimated Significant Figures: Measurements have uncertainty when reading an instrument with a scale (thermometer, ruler, etc.) 45.872 the last digit of a measurement is Certain - measure/estimate one place further than you have marks on the scale Example: this scale has marks every 1 gram, so your measurement should be one place further. (to the tenth of a gram) Measure this sample in grams: Which number is certain? Which number is an estimate? Practice: What are the readings to the correct number of digits? ONCE 50 1 Ocm ruler J40 Close-up View 570 100m thermometer graduated cylinder beaker Significant figures express precision Which of these two numbers is more precise? Why? 12.3 cm or 12.30 cm The non-placeholding digits in a reported measurement are called significant figures. - The more significant figures there are the more the measurement