OPEN NUMBER SENTENCES What Are Open Number Sentences? • Open number sentences are equations that give one part of the equation along with the answer. • In order to solve an open number sentence, the inverse operation is used. How to solve open number sentences: • When solving an open number sentence, first look at the operation that is being used in the number sentence. The inverse operation will need to be used. • If it is an addition problem, you will need to use subtraction. For example: Solve 5 + ___ = 7. To find the missing part of the equation, you will need to subtract 5 from both sides. 5 + ___ = 7 -5 -5 By subtracting 5 from both sides, we find that the answer is 2! 5 + 2 = 7 • If it is a subtraction problem, you will need to use addition. For example: Solve ___ – 8 = 4 To find the missing part of the equation, you will need to add 8 to both sides. – 8 = 4 +8 +8 By adding 8 to both sides, you see the answer is 12! 12 – 8 = 4 © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.
Try This! Fill in the correct answer for each open number sentence. 8 + ___ = 13 ___ - 3 = 11 3 + ___ = 15 ___ - 5 = 15 ___ + 17 = 22 ___ - 4 = 18 © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.