GRADE 2 · ALBERTAOUTCOME AB-MAT2-N2
L3 · Strategies: making multiples of ten and using doubles
Learning goal
“I can add by making a multiple of ten first, and I can use a double I know to answer a near double.”
Multiple of ten — a number made only of tens: 10, 20, 30, 40, and so on.
Double — a number added to itself, like 6 + 6 or 20 + 20.
Near double — an addition one more or one less than a double, like 25 + 26.
Strategy — a smart way you choose to solve a problem.
Worked example
Add 38 + 7. Step 1 - LOOK AHEAD: 38 is close to 40, a multiple of ten. Step 2 - SPLIT THE 7: 38 needs 2 to reach 40, so split 7 into 2 and 5. Step 3 - JUMP: 38 + 2 = 40, then 40 + 5 = 45. So 38 + 7 = 45. Land on the ten first; the rest is easy.
Check yourself — explain it
Why do we split 7 into 2 and 5 in 38 + 7?
Paired problem — example still visible
46 + 5: split the 5 to land on 50. -> 46 + 4 = 50, then 50 + 1 = 51
Faded completion — last step is yours
29 + 8: 29 + 1 = 30, then 30 + ___ = ___ -> 7; 37
Ready to practise?
10 scored questions with a 3-rung hint ladder. Mastery needs 8/10 plus both gate questions.