Fishtank Learning

6th Grade Math
Unit 4: Rational Numbers
Lesson 7

Objective

Compare and interpret the order of rational numbers for real-word contexts.

Anchor Problems - Problem 1

The Navy Seals are practicing new techniques with two submarines. A blue submarine is 425 feet below sea level, while a red submarine is 375 feet below sea level.

Which number line represents the situation? Which point represents each color submarine? Justify your response.

Guiding Questions

What does zero represent in this situation?
What integers represent the elevation of the two submarines?
Which submarine is farther below sea level? How do you know?
If a green submarine is farther below sea level than the blue submarine, what could be a possible elevation for it?

Notes

This Anchor Problem asks students to reason about integers in context and explain their reasoning using the number line. For example, students may describe the blue submarine as below the red submarine because $${-425}$$ is to the left of $${-375}$$ on the number line.

Anchor Problems - Problem 2

The record low temperatures for a town in Maine are $$-20$$°F for January and $$-19$$°F for February.
Order the numbers from least to greatest.

Anchor Problems - Problem 3

The account balances of four bank customers are shown below.

Customer	Account balance
Leonard	$$-$8.90$$
Michelle	$$$8.60$$
Nikhil	$$-$15.50$$
Olivia	$$-$9.00$$

a. Order the account balances from least to greatest.

b. Who has the greater account balance: Olivia or Leonard? Explain your reasoning.

Guiding Questions

What does a negative number mean in this context?
What does a positive number mean?
Who has more money in their account, Leonard or Michelle?
Who has the most money in their account? How can you tell right away?
Where would each value be placed on a number line?
Challenge: Leonard's account balance changes so he now has more money in his account than Nikhil but less than Olivia. Name a possible account balance for Leonard and state how much money his account changed by.

Notes

This is a good opportunity to have students work in pairs to share their reasoning and listen to the reasoning of their peers.

Problem Set

View Problem Set

Target Task

The number line below shows the elevations, in meters, of two different sea animals in the ocean.

a. Order the elevations of the sea animals from least to greatest.

b. A third sea animal, C, is located at an elevation that is greater than sea animal A. Name a possible elevation for sea animal C.