Scientific+Notation+LP

= Title: Scientific Notation and You! =

= Lesson Overview: = This lesson is intended as a review of scientific notation and how to convert numbers from standard form to scientific notation and vice versa. Students need to be able to understand and use scientific notation with ease in order to calculate moles, wavelengths, electrical charges, and atomic radius among other things. Students in the College Prep chemistry class must meet minimum math requirements to be admitted to the class, so the concept of scientific notation should be review for the students.

GSE:
This lesson is designed to prepare students with the background knowledge necessary to be able to meet the following GSE in future lessons. PS2 (Ext)– 6 Students demonstrate an understanding of physical, chemical, and nuclear changes by… 6aa using chemical equations and information about molar masses to predict quantitatively the masses of reactants and products in chemical reactions. = Objectives: = Correctly express numbers in terms of scientific notation. Correctly convert numbers from scientific notation to standard form. = Materials: = Scientific Notation handout White boards Dry erase markers Example Problems for white board work: Scientific Notation HW = Safety Issues: = None

= Instruction =

Opening:
Who remembers what the purpose of our activity was last week? Can someone explain the difference between precision and accuracy? Why do we care about significant digits in science?

By show of hands who has used scientific notation before? And who is comfortable with it?

Learning Activities:
"**Who invented scientific notation?**Exponents were used to handle very large numbers as far back as Archimedes (200 BC). He estimated how many grains of sand would fill the universe using a form of exponents. However, exponential notation as we use it today wasn't invented until the 1600 (by Descartes) and actual scientific notation didn't become 'scientific' until sometime in the 1930s or 1940s." (per http://www.mathworksheetsworld.com/bytopic/scinotation.html)

Why we use scientific notation -- Easy way to express really large numbers and really small numbers. "A very large or small number in the decimal system requires too many zeros to actually write out. For instance, a million has six zeros - 1,000,000 and is moderately sized, but a million trillion would take 18 zeros (1,000,000,000,000,000,000). Because such large numbers differ by some power of 10 (each power of 10 shifts a number left or right one place) it is more convenient to use 1 x 1018 and take advantage of the fact that the exponent (18) when used with 10, means 18 zeros. This works for small numbers also if the exponent is negative. So, 0.000001 is the same as 1 x 10-6. The real advantage comes when large or small numbers have to be multiplied or divided. The rules of exponents allow us to simply add or subtract the exponents as long as they share 10 as the base." (per http://www.mathworksheetsworld.com/bytopic/scinotation.html)

Discuss use of zeros as place holders. Review place values:
 * In whole numbers: ones, tens, hundreds, thousands, ten thousands, hundred thousands, millions, etc
 * In decimals: tenths, hundredths, thousandths, ten thousandths, hundred thousandths, millionths

In Scientific Notation, the exponent of the 10 is positive for numbers greater than 1, and negative for numbers less than 1 (decimals)

Scientific Notation essential when counting/calculating moles of chemicals.

Do 4 practice problems on the board while calling on students to answer.

Have students pair up, pass out one white board & dry erase marker for each pair. Write a problem on the board, first pair to respond correctly gets 2 points, each pair to respond correctly gets 1 point. First pair to 20 points gets 3 extra credit points on the quiz, if all pairs get to 20 points before end of lesson, rest of students get 2 extra credit points on quiz.

Closing:
So why did we learn about scientific notation today? How does it relate to significant digits? Remember: Quiz Wednesday!!!!! = Homework = Do homework worksheet. Study for quiz on Wednesday: Sci. Not. & Sig. Figs

= Assessment = Informal Assessment: Student responses during white board activity

Formal Assessment: Homework worksheet, Quiz next class period