# Bellwork - Ms. Gibbs' 7th Grade Mathematics Class Bell Work 1. What do you do to the exponents when taking the quotient of powers? When taking the quotient of powers with like bases I subtract the exponents. 2. How is this different from the product of powers? The product of powers is different from the quotient of powers because I add the exponents instead of subtracting them. 3. Evaluate the following expressions using positive exponents. **Have your homework out for me to check! (workbook pages 211

and 213) Will these products be positive or negative? How do you know? 8 times Positive (There is an even number of negative factors) 9 times Negative (There is an odd number of negative

factors) Is it necessary to do all of the calculations to determine the sign of the product? Why or why not? No, the sign can be determined by the number of negative factors. 95 times Negative (odd number of negatives)

122 times Fill in the blacks about whether the number is positive or negative. a. If n is a positive even number, POSITIVE then is __________________________________ _. NEGATIVE b. If n is a positive odd number,

then is __________________________________ . Product and Quotient of Powers a. Let x be a positive integer. If , what is x? - - +++++ +++ Rally Coach

Re-write the following numbers using Scientific Notation 1. 81,000 2. 1,396,000 3. 80,000,000 4. 0.00015 5. 0.0000317 **When your entire team is done check your answers! Rally Coach Re-write

the following numbers in Standard Form. **When your entire team is done check your answers! Comparing Numbers Written in Scientific Notation a. The Fornax Dwarf galaxy is light-years away from Earth, while Andromeda is light-years away from Earth. Which is

closer to Earth? In order to compare their distances we need both numbers to be products of the same power. and Now we can compare their distances from Earth. Therefore, Fornax Dwarf is closer to Earth. Comparing Numbers Written in Scientific Notation b. The average lifetime of the tau lepton is

seconds, and the average lifetime of the neutral pion is seconds. Explain which subatomic particle has a longer average lifetime. Therefore, Tau Lepton has a longer average lifetime. c. Compare and . They are both products of the same power so we only need to compare 9.3 and 9.287910 Therefore,

Comparing Numbers Written in Scientific Notation Chris said that because 5.3 has fewer digits than 5.301. Show that even though his answer is correct, his reasoning is flawed. Show him an example to illustrate that his reasoning would result in an incorrect answer. Explain. Operations with Numbers in Scientific Notation a. The speed of light is 300,000,000 meters per second. The sun is approximately meters form

Earth. How many seconds does it take for sunlight to reach Earth? First we need to put 300,000,000 into scientific notation: We can then set up a ratio to find out how long it will take. It takes 500 seconds for sunlight to reach the Earth. Operations with Numbers in Scientific Notation b. The mass of the moon is about kg. It would take approximately 26,000,000 moons to equal

the mass of the sun. Determine the mass of the sun. First put 26,000,000 into scientific notation: Then you much multiply the mass of the moon by When taking the product of powers you add the exponents when there are like bases. Multiply 7.3 and 2.6 and add the exponents. The sun has a mass of kg. Operations with Numbers in Scientific Notation a. The mass of the Earth is kg. The mass of Pluto is 13,000,000,000,000,000,000,000 kg.

Compared to Pluto, how much greater is Earths mass than Plutos mass? b. Us the information in Exercises 2 and 3, find the combined mass of the moon, Earth, and Pluto. Efficacy of Scientific Notation a. The mass of a proton is 0.000000000000000000000000001672622 kg. 1.672622 10 27

In scientific notation it is: _____________________________________________________ b. The mass of an electron is 31 9.10938291 10 0.000000000000000000000000000000910938291 kg. In scientific notation it is: _____________________________________________________ Efficacy of Scientific

Notation a. Write the ratio that compares the mass of a proton to the mass of an electron. b. Compute how many times heavier a proton is than an electron (that is, find the value of the ratio). Round your final answer to the nearest one. Efficacy of Scientific Notation The geographic area of California is 163,696 sq. mi., and the geographic area of the U.S. is

3,794,101 sq. mi. Lets round off these figures to . In terms of area, roughly estimate how many Californias would make up one U.S. Then compute the answer to the nearest ones. Efficacy of Scientific Notation The average distance from Earth to the moon is about km, and the distance from Earth to Mars is approximately km in year 2014. On this simplistic level, how much further is traveling from Earth to Mars than from Earth to the moon?