GRADE 1 · ALBERTAOUTCOME AB-G1-1N3
L3 · Fair halves: checking that both halves are the same size
Learning goal
“I can check that two halves are the same size - and fix a split that is not fair.”
Fair — a split is fair when both halves are the same size.
Check — count both groups, or match the pieces, to see if they are equal.
Same size — neither half is bigger; the two halves match.
Worked example
Claim: "One-half of 8 is 3." Check it. If one group is 3, the other group is 5 (3 + 5 = 8). Count both groups: 3 and 5. They do not match. The claim is wrong. Fix it: move 1 counter over. Now the groups are 4 and 4. One-half of 8 is 4. Say it plainly: to check a half, look at BOTH groups. They must be the same number.
Check yourself — explain it
How do we check a one-half claim?
Paired problem — example still visible
Check the claim: "One-half of 6 is 3." -> The claim is right (groups of 3 and 3 match; 3 + 3 = 6)
Faded completion — last step is yours
"Groups of 2 and 4 make 6. They are not equal, so 4 is not one-___ of 6." -> half (one-half)
Ready to practise?
8 scored questions with a 3-rung hint ladder. Mastery needs 7/8 plus both gate questions.