1. Bell Ringer Simplify by combining like terms: 1. 4x + 3y – 5y + 2x = 6x – 2y 2. -5x – 3y + 2x – 7y = -3x – 10y 3. 9 + 3y + 4x – 6y = 4x – 3y + 9

2. Quiz Results are online… I’ll pass back papers when those who were absent take the quiz. In the meantime, we will begin…

3. Scientific Notation NCP 504: Work with scientific notation

4. What is Scientific Notation? It is a way to write very large or very small numbers in a more convenient way. It also allows people to avoid mistakes that occur when writing too many zeroes.

5. Scientific Notation 1.23 x 10 8 Coefficient – It is always a single digit followed by a decimal point and then the rest of the digits. Base – In scientific notation, it is always written as powers of ten. Exponent The standard form of this number is 123,000,000! We will look at how to do this next…

6. When using Scientific Notation, there are two kinds of exponents: positive and negative. Positive Exponent: 2.35 x 10 8 Negative Exponent: 3.97 x 10 -7

7. When changing scientific notation to standard notation, the exponent tells you if you should move the decimal: With a positive exponent, move the decimal to the right: 4.08 x 10 3 = 4 0 8 4,080 Don’t forget to fill in the zeroes! 0

8. When changing scientific notation to standard notation, the exponent tells you if you should move the decimal: With a negative exponent, move the decimal to the left: 4.08 x 10 -3 = 4 0 8 =.00408 Don’t forget to fill in the zeroes! 0 0

9. Think of it this way… If an exponent is positive, the number gets larger, so move the decimal to the right. If an exponent is negative, the number gets smaller, so move the decimal to the left.

10. The exponent also tells how many spaces to move the decimal: 4.08 x 10 3 = 4 0 8 4080 In this problem, the exponent is +3, so the decimal moves 3 spaces to the right. 0

11. The exponent also tells how many spaces to move the decimal: 4.08 x 10 -3 = 4 0 8.00408 In this problem, the exponent is -3, so the decimal moves 3 spaces to the left. 0 0

12. Try changing these numbers from Scientific Notation to Standard Notation: 1)9.67 x 10 4 2)7.458 x 10 -3 3)8.51 x 10 7 4)1.09 x 10 -5 96,700.007458 85,100,000.0000109

13. When changing from Standard Notation to Scientific Notation: 1) First, move the decimal after the first whole number: 3 2 5 0 2) Second, add your multiplication sign and your base (10). 3.250 x 10 3) Count how many spaces the decimal moved and this is the exponent. 3.250 x 10 3 = 3.250

14. When changing from Standard Notation to Scientific Notation: 4) See if the original number is greater than or less than one. –If the number is greater than one, the exponent will be positive. 348,943 = 3.489 x 10 5 –If the number is less than one, the exponent will be negative..000672 = 6.72 x 10 -4

15. Try changing these numbers from Standard Notation to Scientific Notation: 1)980,000 2).000345 3).083789 4)5673 9.8 x 10 5 3.45 x 10 -4 8.3789 x 10 -2 5.673 x 10 3