GRADE 2 · ALBERTAOUTCOME AB-MAT2-N1
L2 · Skip counting by 20s, 25s, and 50s from 0
Learning goal
“I can skip count by 20s, 25s, and 50s, starting at 0.”
Count by 20s — counting where each number is 20 more: 0, 20, 40, 60, ...
Count by 25s — counting where each number is 25 more: 0, 25, 50, 75, ...
Count by 50s — counting where each number is 50 more: 0, 50, 100, 150, ...
Step — the size of the jump between one landing and the next. The step is 20 when counting by 20s.
Worked example
Count by 20s from 0: 0, 20, ___, ___. Step 1 (the step): each landing is 20 more - two whole tens at a time. Step 2 (hop): 0, 20, 40, 60. Counting by 20s sounds like counting by 2s with a zero tacked on: 2, 4, 6 -> 20, 40, 60. Step 3 (the 50s are bigger): by 50s the landings are 0, 50, 100, 150, 200 - each jump is half a hundred. Say it plainly: these counts always start at 0, and the step size is in the name.
Check yourself — explain it
Counting by 20s sounds like counting by 2s with a zero on the end because...
Paired problem — example still visible
Count by 50s: 0, 50, 100, ___, ___ -> 150, 200
Faded completion — last step is yours
"Count by 20s: 0, 20, 40, 60, ___" -> 80
Ready to practise?
10 scored questions with a 3-rung hint ladder. Mastery needs 8/10 plus both gate questions.