Unit 7 - Lesson 15 - Grade 8: Illustrative Mathematics

Diego, Kiran, and Clare were wondering:“If Neptune and Saturn were side by side, would they be wider than Jupiter?” They try to add the diameters, 4.7 x 104 km and 1.2 x 105 km. Here are the ways they approached the problem.Diego says, “When we add the distances, we will get 4.7 + 1.2 = 5.9 . The exponent will be 9. So the two planets are 5.9 x 109 km side by side.”Kiran wrote 4.7 x 104 as 47,000 and 1.2 x 105 as 120,000 and added them:📷Clare says, “I think you can’t add unless they are the same power of 10.” She adds 4.7 x 104 km and 12 x 104 to get 16.7 x 104.

Jupiter has a diameter of 1.43 x 105. Which is wider, Neptune and Saturn put side by side, or Jupiter?

When you add the distances of Mercury, Venus, Earth, and Mars from the Sun, would you reach as far as Jupiter?

Add all the diameters of all the planets except the Sun. Which is wider, all of these objects side by side, or the Sun? Draw a picture that is close to scale.

On a farm there was a cow. And on the farm there were 2 sheep. There were also 3 chickens. What is the total mass of the 1 cow, the 2 sheep, the 3 chickens, and the 1 farmer on the farm?

Make a conjecture about how many ants might be on the farm. If you added all these ants into the previous question, how would that affect your answer for the total mass of all the animals?