Exploring Rational Expressions in Grade 8 Math

This video tutorial covers Math 8 Unit 7 Lesson 15, focusing on adding and subtracting with scientific notation. It begins with mental math exercises to identify non-zero digits, followed by practical applications in measuring planetary distances. The tutorial also includes comparisons of celestial distances, mass calculations on a farm, graph interpretation, and problem-solving techniques. The session concludes with step-by-step equation solving, providing a comprehensive understanding of scientific notation and its applications.

How many non-zero digits are there in the product of 3 times 2?

• Four

• Three

• Two

• One

What is the correct way to add 4.7 times 10^4 and 1.2 times 10^5?

• 0.47 times 10^5 + 1.2 times 10^5 = 1.67 times 10^5

• 4.7 times 10^4 + 12 times 10^4 = 16.7 times 10^4

• 4.7 times 10^4 + 1.2 times 10^5 = 5.9 times 10^9

• 4.7 + 1.2 = 5.9 times 10^9

Which is wider: Neptune and Saturn combined or Jupiter?

• Cannot be determined

• Jupiter

• They are the same width

• Neptune and Saturn combined

When adding the distances of Mercury, Venus, Earth, and Mars, do they reach as far as Jupiter?

• Yes, they reach farther than Jupiter

• No, they do not reach as far as Jupiter

• They reach exactly as far as Jupiter

• Cannot be determined

What is the total mass of one cow, two sheep, and three chickens?

• 588 kg

• 591 kg

• 600 kg

• 620 kg

What is the total mass of a human, a blue whale, and six ants?

• 190,000.062123418 kg

• 190,000.062 kg

• 190,000.062123418 kg

• 190,000.062 kg

Which is greater: the number of bacteria or the number of all the animals in the table put together?

• Number of all animals

• Number of bacteria

• They are equal

• Cannot be determined

What is the result of 3.7 minus 3.3 times 10^6?

• 0.4 times 10^5

• 0.4 times 10^6

• 4 times 10^6

• 4 times 10^5

What is the slope of the line between six and eight minutes in the graph?

• 1 km/min

• 0.5 km/min

• 1.5 km/min

• 2 km/min

How many apples are needed to have eight fruits that cost ten dollars?

• Five

• Four

• Six

• Seven