GRADE 1 · ALBERTAOUTCOME AB-G1-1N2
L3 · Fact families: facts that belong together
Learning goal
“I can use the facts in a fact family: two additions and two subtractions with the same three numbers.”
Fact family — a group of facts that all use the same three numbers.
Addition fact — a fact with a + sign: two parts make a whole.
Subtraction fact — a fact with a − sign: the whole take away one part leaves the other part.
Worked example
Build the family for parts 3 and 5, whole 8. Addition facts: 3 + 5 = 8 and 5 + 3 = 8 (the parts trade places; the whole stays 8). Subtraction facts: 8 − 3 = 5 and 8 − 5 = 3 (the whole take away one part leaves the other part). Four facts, and every fact uses only 3, 5, and 8.
Check yourself — explain it
Why is 8 − 3 = 5 in this family?
Paired problem — example still visible
The family is 2, 6, 8. We know 2 + 6 = 8. What is 8 − 6? -> 2 (the whole take away the part 6 leaves the other part, 2)
Faded completion — last step is yours
"Family 4, 5, 9: 4 + 5 = 9 and 5 + 4 = 9. Now take away: 9 − 4 = ___" -> 5
Ready to practise?
8 scored questions with a 3-rung hint ladder. Mastery needs 7/8 plus both gate questions.