GRADE 1 · ALBERTAOUTCOME AB-G1-1N2
L4 · Zeros and order: adding 0, subtracting 0, and why order matters
Learning goal
“I can add or subtract 0, and I know that swapping numbers changes a subtraction.”
Zero — none; nothing there.
Order — which number comes first.
Swap — trade places.
Worked example
7 dots sit on a mat. Add 0 dots: still 7 dots. 7 + 0 = 7. Take away 0 dots: still 7 dots. 7 - 0 = 7. Say it plainly: adding nothing or taking away nothing leaves the number the same. And if you take away ALL of a group, nothing is left: 9 - 9 = 0.
Check yourself — explain it
Adding 0...
Paired problem — example still visible
12 + 0 = 12 and 12 - 0 = 12
Faded completion — last step is yours
"15 - 0 = ___ and 0 + 15 = ___." -> 15; 15
Ready to practise?
8 scored questions with a 3-rung hint ladder. Mastery needs 7/8 plus both gate questions.