Name:________________________________________________________________________________Date:_____/_____/__________ Brain blitz/ warm-up Get Homework out FIRST! Then, begin warm-up. Fill-in-the-table: 1) 245,000,000,000 2) 6,050,000 3) 5.6 x 106 4) 4.02 x 104 5) Order the following from least to great: 8.02 x 102 Answer: 3.9 x 105 9.1 x 105 2.05 x 106 Today’s lesson . . . What: Scientific Notation with Negative exponents Why: To convert between numbers written in scientific notation (w/ negative exponents) and numbers written in standard form. Who remembers what it is? We use scientific notation to write very LARGE ___________________ or very __________________ small numbers. Scientific notation is a # written as a multiplication ____________________________________ sentence. • The leading factor MUST be a number greater than or equal to 1, ten (10) but less than _____________. • The second factor must be a power _________________ of 10. Example: 2.5 x 10-5 What does it mean when the exponent is negative? It means that the # will be SUPER SMALL– a DECIMAL!! From scientific notation . . . Guided practice: # Scientific Notation Standard Form We need 3 zeros in FRONT! 1. 2.8 x 10 -4 0.00028 Count digits to the LEFT of decimal point! How many extra zeros do we need? We need 6 zeros in FRONT! 2. 4.05 x 10 -7 0.000000405 On YOUR OWN: # Scientific Notation Standard Form 3. 9 x 10 -6 0.000009 4. 7.02 x 10 -5 0.0000702 From standard form . . . As soon as you see a DECIMAL number, think NEGATIVE EXPONENT!!!! Guided practice: # 1. 2. Scientific Notation 3.4 x 10-5 Notice the negative exponent! 1.02 x 10-4 We still need to move decimal so that we make a number bigger than 1, but less than 10. Standard Form 5 jumps! 0 000034 0 000102 4 jumps! 3. 7 x 10-6 6 jumps! 0 000007 ON YOUR OWN: # Scientific Notation Standard Form 4. 2.1 x 10-6 0.0000021 5. 4.05 x 10-3 0.00405 Mixed practice: When do we need a positive exponent and when do we need a negative exponent??? # Scientific Notation Standard Form 1 2.5 x 108 250,000,000 2 7.5 x 10-7 0.00000075 3 2.09 x 10-3 0.00209 4 5.723 x 109 5,723,000,000 5 3.6 x 104 36,000 6 9.004 x 107 90,040,000 7 5.9 x 10-6 0.0000059 8 7.2 x 10-3 0.0072 IXL HOmework A.8 - Scientific Notation A.9 - Compare Numbers Written in Scientific Notation EARN a Smart Score of 70 & work for at least 10 minutes! DON’T FORGET TO LOG IN! (You won’t receive credit for doing your homework if you are not logged in!) TO LOG IN: CLICK on the IXL button on the Simpson Home Page (left side) Username: given to you by your teacher (Usually your initial of first name, and full last name) Password: math7 Once you are logged in, you can click on the links above to get to the skill(s) assigned for homework OR you can do the following: • • CLICK on MATH • CLICK on 7th GRADE CLICK on the skill(s) assigned for homework EARN a Smart Score of 70 on the assigned skill(s), then you are done! (Spend at least 10 minutes practicing.) END OF LESSON The next slides are student copies of the notes for this lesson. These notes were handed out in class and filled-in as the lesson progressed. Math-7 NOTES NAME: DATE: ______/_______/_______ What: Scientific Notation with Negative Exponents Why: To convert between #’s written in scientific notation and #’s written in standard form. What is it? We use scientific notation to write very ____________________________ or very _________________________ numbers. Scientific Notation: a # written as a _____________________________ sentence. • The leading factor MUST be a number greater than or equal to 1, but less than ________________. • The second factor must be a ________________________ of 10. Example: 2.5 x 10-5 From scientific notation . . . Count digits to the LEFT of decimal point! How many extra zeros do we need? Place zeros IN FRONT! examples: # Scientific Notation 1. 2.8 x 10 -4 2. 4.05 x 10 -7 3. 9 x 10 -6 4. 7.02 x 10 -5 Standard Form From standard form . . . We still need to move decimal so that we make a number bigger than 1, but less than 10. Remember to use a NEGATIVE exponent!! examples: # Scientific Notation Standard Form 1. 0.000034 2. 0.000102 3. 0.000007 4. 0.0000021 5. 0.00405 Mixed practice: When do we need a positive exponent and when do we need a negative exponent??? # Scientific Notation Standard Form 1 250,000,000 2 0.00000075 3 0.00209 4 5,723,000,000 5 3.6 x 104 6 9.004 x 107 7 5.9 x 10-6 8 7.2 x 10-3 NAME:__________________________________________________________________________ DATE: ______/_______/____________ EXIT TICKET “Scientific Notation” Fill in the table: 1) 702,200,000 2) 0.000438 3) 8.91 x 107 4) 5.1 x 10-7 5) Order the following from least to greatest: 1.9 x 108 4.4 x 106 9.25 x 103 6.05 x 108 Answer: NAME:__________________________________________________________________________ DATE: ______/_______/____________ EXIT TICKET “Scientific Notation” Fill in the table: 1) 702,200,000 2) 0.000438 3) 8.91 x 107 4) 5.1 x 10-7 5) Order the following from least to greatest: 1.9 x 108 Answer: 4.4 x 106 9.25 x 103 6.05 x 108 NAME:__________________________________________________________________________ DATE: ______/_______/____________ INDIVIDUAL practice “Scientific Notation” Remember: A really BIG # needs a positive exponent. A # less than one needs a negative exponent! 4.5 x 100 --because the decimal pt. does not need to move. Continued . . . SOL PREP