190 likes | 326 Views
Targeted Instruction. Warm up. Find each value. 1. 9 2 3. 15 2 5. 10 2 2. 12 2 4. 10 3 6. 10 4 7. Each day, Lowell runs one more lap than he did the day before. After seven days he has run 77 laps. Hap many laps did he run on the first day?. Check HW. Scientific Notation.
E N D
Warm up Find each value. 1. 92 3. 152 5. 102 2. 122 4. 103 6. 104 7. Each day, Lowell runs one more lap than he did the day before. After seven days he has run 77 laps. Hap many laps did he run on the first day?
Scientific Notation 7th Grade Mathematics
Scientific Notation • Today we will learn to express large numbers in scientific notation.
Vocabulary • Define the following terms in your notebook: 1. standard form 2. scientific notation
Multiplying by powers of 10 • Multiply 21 • 104 • Multiply 14 • 103 • Multiply 25 • 102 • Multiply 18 • 104 • Multiply 40 • 104
Multiplying by powers of ten mentally Find each product. 1. 137 • 103 2. 46.2 • 105 3. 212 • 104 4. 31.6 • 103
Standard Form • Numbers are usually written in standard form. • Example: 17,900,000
Scientific Notation Scientific notation is a kind of shorthand that can be used to write large numbers. Numbers written in scientific notation are written as the product of two factors. Example: 9,580,000 = 9.58 x 106
Writing numbers in scientific notation Write each number in scientific notation. • 813,000,000 • 4,340,000 • 327,000,000 • 428,000 • 1,610,000
Writing numbers in standard form Pluto is about 3.7 x 109 miles from the Sun. Write this distance in standard form.
Writing numbers in standard form The population in China in the year 2000 was estimated to be about 1.262 x 109. Write this number in standard form.
Word problem • In a vacuum, light travels at a speed of about nine hundred and eighty million feel per second. Write this speed in scientific notation.
Wring in standard form • Earth is about 9.292 x 107 miles from the Sun. Write this number in standard form.
Interesting estimates • 1010 is about the number of starts in our galaxy. • 1020 is the total number of starts in the universe. • 1030 kilograms is about the mass of the Sun. • 1067 is about the total number of ways to arrange 52 cards. • 1040,000 is about the chance of a monkey’s correctly typing Hamlet by hitting random keys on a computer keyboard.
Comparing The table lists some very long distances. Put them in order from greatest to least.
Homework Textbook p. 66 (30-47)