3.11 Open Sentences

Homework Review

Mental Math Find the sum or difference.

16 – 5 = ____

8 + 14 = ____

180 + 50 = ____

210 – 30 = ____

92 + 59 = ____

184 – 126 = ____

Math Message

Write your defense in your Math Notebook.

What is an OPEN SENTENCE?

In this sentence, the letter x stands for the missing number. It is called a variable.

You could have also written it as:

What number could you write in place of the

to change

into a true number sentence?

Open Sentences

A sentence that has a variable in it, like the one above, is called an open sentence.

To solve the open sentence, replace the variable with a number that makes the sentence true.

The number that makes the number sentence true is called the solution.

Let’s try some more…

Rewrite each number sentence on your whiteboard with the solution in

place of the variable.

Circle the solution.

Find the solutions…

Broken Calculator Activity

Solve it using your calculator, but WITHOUT using the minus key.

More Broken Calculator Problems…

Partner Work – Math Journal page 73.

Independent Work – Math Journal page 74.

Independent Work – Math Journal page 75.

Tonight’s Homework

Math Boxes