4-6 Understand and Write Inequalities

4-6 Understand and Write Inequalities

I CAN
understand and write an inequality that describes a real-world situation.

Try It!

The record time for the girls' 50-meter freestyle swimming competition is 24.49 seconds. Camila has been training and wants to break the record. What are some possible times Camila would have to swim to break the current record? (Write at least 3.)

Multiple Choice

Chad won a blue ribbon for growing the heaviest pumpkin at the Pumpkinfest. It weighed 217 pounds. What could be the weight of other pumpkins in the contest? Write your answer as a mathematical statement.

• w > 217

• w < 217

• $$w\le217$$

• $$w\ge217$$

Open Ended

The record time for the girls' 50-meter freestyle swimming competition is 24.49 seconds. Camila has been training and wants to break the record. What is a possible time Camila would have to swim to break the current record?

KEY CONCEPT
How can you write an inequality to describe a situation?

Multiple Choice

What is the difference between an EQUATION with a variable and an INEQUALITY with a variable?

• Equations have multiple answers. Inequalities have only 1 answer.

• Equations only have 1 solution. Inequalities have many solutions.

• Inequalities are always more complex than equations.

• Inequalities have 1 solution.

What are some ages of children who must be accompanied by an adult?

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How can we write an inequality to describe the ages of the children who must be accompanied by an adult at the sledding hill?

What are some ages of children who must be accompanied by an adult?

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How can we write an inequality to describe the ages of the children who must be accompanied by an adult at the sledding hill?

​You can show some of the ages on a number line.

Let a represent the ages of children who must be accompanied by an adult. Use the less than symbol (<) to write the inequality.

Multiple Choice

Which inequality describes the ages of the children who must be accompanied by an adult at the sledding hill? (Let a represent the ages of children.)

• a < 8

• a > 8

• a = 8

• $$a\le8$$

Multiple Choice

The manager of a grocery store made a number line to show the number of items the shopper can have when using Checkout 2. The manager then put up a sign at Checkout 2 that says, “At least 5 Items.”

Is the number line showing "at least 5 items" correct or incorrect?

• Correct. The number line shows values greater than or equal to 5.

• Incorrect. The number line shows values less than or equal to 5.

Multiple Choice

Write an inequality to represent the situation.

Fatima's age, 𝙛, is not 4 years old.

• $$f\ne4$$

• $$f\le4$$

• $$f\ge4$$

• $$f=4$$

Check Your Understanding!

Multiple Choice

The width of the picture, w, is shorter than 8.5 inches

• w < 8.5

• w > 8.5

• $$w\ge8.5$$

• $$w\le8.5$$

Multiple Choice

Steve’s height, h, is at least 48 inches

• $$h>48$$

• $$h<48$$

• $$h\le48$$

• $$h\ge48$$

Multiple Choice

The value, v, does not equal $$2\frac{1}{2}$$

• v = $$2\frac{1}{2}$$

• $$v\ \ne2\frac{1}{2}$$

• v > $$2\frac{1}{2}$$

• v < $$2\frac{1}{2}$$

Multiple Choice

The number of quarters, q, in the jar is less than 75

• $$q\ \ge\ 75$$

• $$q\le\ 75$$

• q > 75

• q < 75

Multiple Choice

The length of the fish a fisherman catches, f, must be at least 10 inches for him to keep it.

• f > 10

• f < 10

• $$f\le10$$

• $$f\ge10$$