GRADE 3 · ALBERTAOUTCOME AB-G3-3N3
L3 · Missing quantities: a × □ = c, □ × b = c, e ÷ □ = g, □ ÷ f = g
Learning goal
“I can find a missing number in a multiplication or division sentence - a missing factor, a missing divisor, or a missing dividend - by using the fact family.”
Missing quantity — the unknown number in a number sentence, written as □.
Missing factor — the □ in a multiplication: 9 × □ = 72. Find it by dividing: 72 ÷ 9.
Missing dividend — the □ that starts a division: □ ÷ 5 = 7. Find it by multiplying: 5 × 7.
Missing divisor — the □ that splits in a division: 54 ÷ □ = 6. Find it by dividing: 54 ÷ 6.
Worked example
□ × 6 = 42. The □ is a factor. Factors are found by dividing the product by the known factor: 42 ÷ 6 = 7. So □ = 7. Check by putting it back: 7 × 6 = 42. It works in the other seat too: 8 × □ = 56 -> 56 ÷ 8 = 7 -> □ = 7. Say it plainly: to find a missing factor, DIVIDE. The family does the work.
Check yourself — explain it
Why do we divide to find a missing factor?
Paired problem — example still visible
□ × 9 = 63 -> 7 (63 ÷ 9 = 7)
Faded completion — last step is yours
"7 × □ = 49: □ = 49 ÷ 7 = ___." -> 7
Ready to practise?
10 scored questions with a 3-rung hint ladder. Mastery needs 8/10 plus both gate questions.