Web definitions
A fact family is a group of numbers that are related to each other. The numbers can be combined to create 4 number of equations.
These would be the equations that can be made when using the above triangle.
9 + 3 = 12 When adding the answer is called the sum.
3 + 9 = 12
12 - 3 = 9 When subtracting the answer is called the difference.
12 - 9 = 3
When working on fact family triangles the largest number is always at the top of the triangle. The two smaller numbers can be in either of the lower corners. The triangle helps children to visualize the possible equations that can be created using these 3 related numbers.
Consider this word problem:
Susan had 9 pencils. Her grandmother gave her more pencils for her collection. Susan now has 12 pencils. How many pencils did Susan’s grandmother give her?
If a student has an understanding of fact family concept, he/she could rebuild the family.
You know that Susan started out with 9 pencils and ended up with 12 pencils. Thus, you know two of the family members. They are 9 and 12. In math language that translates, 9 pencils + ____ more pencils = 12 pencils or 9 + ? = 12
9 + ? = 12
? + 9 = 12
12 - 9 = ?
12 - ? = 9
Learning Target:
I can use a fact family triangle with 3 related numbers
and write 2 addition and subtraction equations.
I can use my fact families to help solve story problems.
|
|
