In this lesson, students learn about addition fact families. An addition fact family is a set of three numbers related by addition. Two of the numbers make up the third number.
Students are given two members of a fact family and must enter the third number.
In this lesson, students are given a set of objects that represent the numbers in a fact family. They must first write the number family, then write all the fact addition sentences for that fact family. When the two numbers added are different, there are two addition sentences. When the two numbers added are the same, there is one addition sentence.
In this lesson, students are given a set of objects that represent the numbers in a fact family. They must first write the number family, then write all the possible addition and subtraction sentences for that fact family. When the two numbers added are different, there are two addition sentences and two subtraction sentences. When the two numbers added are the same, there is one addition sentence and one subtraction sentence.
In this lesson, students learn to find the missing number in a fact family when one of the numbers is unknown. When the missing number is the number that represents the sum, the student must write an addition sentence to find the missing number. When the missing number is one of the numbers that make up the number that represents the sum, the student must write a subtraction sentence to find the missing number.