Numbers to 100
Counting to a hundred is easy. Understanding that the 3 in 134 means three tens is not, and everything Grade 2 does with arithmetic sits on top of it.
What Alberta asks for by the end of Grade 2
The subject: Mathematics
- Add and subtract numbers within 100.
- Sort shapes, and describe the rule used for sorting.
- Measure length in centimetres.
- Describe how long something takes in days, weeks, months or years.
- Collect data and show it on a graph.
This is the published snapshot rather than the whole program. Grade 2 also covers place value to 100, skip counting, and equal groups as a first step towards multiplication — all of which the addition work depends on.
The words, first
These are the terms a teacher will use at a parent interview, defined before anything below uses them.
| Word | What it means |
|---|---|
| Place value | What a digit means because of where it stands. In 47 the 4 is four tens, not four. |
| Regrouping | Trading ten ones for one ten, or one ten for ten ones. It is what carrying and borrowing actually are. |
| Base-ten blocks | Units, rods of ten and flats of a hundred. The physical version of place value, and worth using until it is not needed. |
| Number line | A line with the numbers marked in order. Adding moves right, subtracting moves left. |
| Skip counting | Counting in steps: 2, 4, 6 or 5, 10, 15. It is the bridge to multiplication. |
| Equal groups | Four groups of three. Grade 2 meets the idea; the times tables come later. |
| Sorting rule | The property used to put things in groups — number of sides, curved or straight, symmetrical or not. Alberta asks the child to say the rule, which is harder than sorting. |
| Centimetre | A hundredth of a metre. Grade 2 measures with a real ruler, having compared directly in Grade 1. |
| Data | Information collected, usually by counting. A graph is a picture of data, and reading one is a separate skill from making one. |
What to do at home
- Trade ten for one — Use coins, blocks or buttons. Regrouping felt once with objects is worth more than any number of worked examples.
- Say the tens out loud — “Forty-seven is four tens and seven.” It sounds obvious to an adult and is the thing being learnt.
- Measure real things — A shoe, a book, a cat if it will hold still. Starting the ruler at the end rather than at zero is the classic error and is best caught at home.
- Skip count on the stairs — In twos, fives and tens. It costs nothing and it is the groundwork for multiplication.
- Graph something they care about — Favourite colours in the family, cars passing the window in ten minutes. Collecting the data is half the outcome.
- Talk about how long — Until a birthday, until the weekend, how long a season lasts. Days, weeks, months and years are surprisingly abstract at seven.
Sheets you can print for this
- How many is that? — hundreds, tens and ones
- Adding within 100 — twelve questions
- Taking away within 100 — twelve questions
- Measure it — in centimetres
- Sort them, then say the rule — 2-d shapes
- Collect it, then graph it — data
The expectations above are paraphrased from Alberta Education's New K–6 curriculum fact sheets, which publish a snapshot of each grade rather than the complete program of studies. Alberta's full programs are at alberta.ca/curriculum.