Wednesday 9.1.10

Today, Mr. Paek started the class by talking about yesterdays scribe post. After going over what was good and what could’ve been changed, he let us go back to our chosen lab groups to finish up the measurement lab.

Most groups just had to measure the mass of four objects, and those objects were: a jumbo paperclip, a piece of paper, a pencil and an empty film canister. We used a balance pan to measure how much each object weighed in grams. Then, after measuring the mass, the last thing to do in the lab was to measure the temperature. We used a thermometer to measure the room temperature and the temperature of tap water in a beaker.

Once everyone finished the lab we regrouped and got four new sheets of paper to tape into our journal. Two of those sheets were about significant figures and the other two were about scientific notation.

The significant figures rules are:       

·         Digits other than zero are always significant

·         Zeros between non-zero digits are always significant

·         Any final zero use after a decimal point is significant

·         Zeros used solely for spacing the decimal point (place holders) are not significant

Examples are in the picture posted.

             Lastly, we ended the class by learning how to round numbers to four significant figures and how to convert measurements into scientific notation. To round numbers to four significant figures you take the first four significant figures and make the rest of the numbers after those zeros. For example 12,345,670 would become 12,350,000 or 0.0657030 would become .06570. Some people were really confused, but after doing a couple of examples we started to get it. Mr. Paek said that we will do some more examples in class tomorrow.