Skill 6B
Fact Families: Related Facts
When a question in a textbook asks for a "related fact," it is asking for the other facts in its fact family.  If you recall from previous skills, a fact family is simply taking the 3 numbers in a math fact and changing the order so the problem is still correct. Therefore, the math fact related to 7+5=12 is 12-7=5.  You can see that all three numbers in the addition number sentence are used in the subtraction fact, but just in a different order..

Which subtraction fact is related to
the number sentence 7 + 5 = 12?

  A. 7 - 5 = 2
  B. 12 - 7 = 5
  C. 5 - 1 = 4
  D. 12 - 6 = 6