# Ontario Grade 2 Mathematics — 23 October 2026

The Grade 2 authoring pass maps the official 2020 curriculum onto the shared taxonomy. All 51 retained source expectations were checked against staging: 39 specific and 12 overall. Source wording and stored hierarchy are unchanged. [Official Ontario source](https://www.dcp.edu.gov.on.ca/en/curriculum/elementary-mathematics/grades/g2-math).

Five topics were added: four focused elementary claims extracted from knowledge already used inside broader topics, and one genuinely absent skill, concurrent events in code. This is not five new gaps between national curricula. Advanced topics retain their integrated procedures; the new elementary claims allow separate assessment without a difficulty-level feature.

| New topic | Role | ID |
|---|---|---|
| Congruent shapes by matching | Extracted elementary claim | `mt_B1lPmwJz0h` |
| What a symbol stands for | Extracted elementary claim | `mt_H4BfdHIdhD` |
| Sorting data by two attributes | Extracted elementary claim | `mt_JEtvvsAQjQ` |
| Concurrent events in code | Previously absent skill | `mt_XXpEz9tyu6` |
| Finding the mode | Extracted elementary claim | `mt_ryyJWULiP5` |

Other expectations use existing claims or combinations of claims. Fractional sharing does not get a topic per number of sharers; numerical limits do not get new copies. Predicting and comparing population modes combines existing prediction/checking with the focused mode claim. Symmetry and fraction gates were corrected where the old prerequisite imposed an unnecessary method. Source-backed Canadian foundations were linked separately.

Three existing evidence records received examples or clarifications within their existing mastery scope: equal grouping via repeated subtraction, qualitative opposite events, and ruler use. Existing descriptions, topic identities, learner estimates, assessment history and teaching research were preserved. The measuring guidance already included an offset or broken ruler.

The resulting graph contains **1,838 topics / 3,878 dependencies**. All 152 Grade 1 Mathematics pairs, all existing non-Ontario pairs and all 41 historical unresolved pairs are preserved. Grade 2 has 124 direct topic-code pairs across 41 directly linked codes. Other overall expectations roll up their children. Source availability, a link and whole-expectation coverage are distinct.

Coverage below is a semantic authoring judgment. Several rows are covered by combinations of claims; succeeding on an elementary task does not certify the full mastery scope of a broader linked topic. A Full label does not certify every learner, all curriculum documents, or the historical Australian Full claims. Full source descriptions and the detailed clause ledger remain in the private evidence repository.

| Code | Coverage judgment | Mapped topics or rollup |
|---|---|---|
| A1 | Full | `mt_WkKkb7W9Qd`, `mt_kJ5wYzO8qC`, `mt_8dstvf-KKb`, `mt_EBYGhd8X3x`, `mt_TMoHjMhRS2`, `mt_20WfHhnL39`, `mt_IM1G_7QzTa`, `mt_f67qGDhyfi`, `mt_LhkP_KKIRS`, `mt_Iwg2diBSyW`, `mt_j8Pv3s7TZR`, `mt_S4G6GLKr1-`, `mt_UGf6jICEhs`, `mt_pAuo9Op89t`, `mt_35-DhMh_Yr`, `mt_QxsoqVUt6u`, `mt_YbX3LD0Eca` |
| B1 | Full | Child-expectation rollup |
| B1.1 | Full | `mt_9L3NQqgqRd`, `mt_F_zEAJ8VIo`, `mt_aPBzD28_mT`, `mt_Bt-iORUzdO`, `mt_8gy7uxRlF6`, `mt_x8TshvbbQT` |
| B1.2 | Full | `mt_AQcVRBddko`, `mt_U0waNfD8PB` |
| B1.3 | Full | `mt_9L3NQqgqRd`, `mt_0ZDouU664X` |
| B1.4 | Full | `mt_M2v1A9OEuM`, `mt_IzQvs7k_sE`, `mt_W3VOAuFwVw` |
| B1.5 | Full | `mt_0u4KLbvBa1`, `mt_hniI4E-OCE` |
| B1.6 | Full | `mt_LpSuPgL31x`, `mt_IfEgu0X449`, `mt_Xp-rj46S2w` |
| B1.7 | Full | `mt_FbDKeLfBCo` |
| B2 | Full | Child-expectation rollup |
| B2.1 | Full | `mt_QCgbiVrwnp`, `mt_T76hKqXf0z`, `mt_ehGS_uVSJv`, `mt_PZ909yPrEC`, `mt_LpSuPgL31x` |
| B2.2 | Full | `mt__t4afSyZRm`, `mt_s2mfRBoTal`, `mt_m1W6nTQJ2b` |
| B2.3 | Full | `mt_AKAtWEwpcj`, `mt_I5j1ZWo2cn`, `mt_PpWSHA-0kv`, `mt_QaYfeVL-0C`, `mt_kJ5wYzO8qC` |
| B2.4 | Full | `mt_glPPG-kTQY`, `mt_UQnAFPs83F`, `mt_cChv2j_-Da`, `mt_yTWxkzzoOZ`, `mt_PgsHGYJMH-` |
| B2.5 | Full | `mt_PZ909yPrEC`, `mt_GRWwTDZ3wD`, `mt_xACS3rWWDp` |
| B2.6 | Full | `mt_LpSuPgL31x` |
| C1 | Full | Child-expectation rollup |
| C1.1 | Full | `mt_ZjIFGc6zPW`, `mt_WXW0hjNhph`, `mt_uG2mjHFOlO` |
| C1.2 | Full | `mt_ZjIFGc6zPW` |
| C1.3 | Full | `mt_W3VOAuFwVw`, `mt_ZjIFGc6zPW`, `mt_fZTn0W_iZR` |
| C1.4 | Full | `mt_W3VOAuFwVw`, `mt_kw7xmp68rU`, `mt_RFeVlw0QvX` |
| C2 | Full | Child-expectation rollup |
| C2.1 | Full | `mt_H4BfdHIdhD` |
| C2.2 | Full | `mt_oIzycTBeE4`, `mt_3JgrHY221M` |
| C2.3 | Full | `mt_Bt-iORUzdO`, `mt_m1W6nTQJ2b`, `mt_oIzycTBeE4` |
| C3 | Full | Child-expectation rollup |
| C3.1 | Full | `mt_XXpEz9tyu6`, `mt_sPV503BQnI` |
| C3.2 | Full | `mt_XXpEz9tyu6`, `mt_5UtPmgdoQ9`, `mt_sPV503BQnI` |
| C4 | Full | `mt_WkKkb7W9Qd`, `mt_fLOkq-HfPB`, `mt_IM1G_7QzTa`, `mt_f67qGDhyfi`, `mt_iQYPw8bMfN` |
| D1 | Full | Child-expectation rollup |
| D1.1 | Full | `mt_JEtvvsAQjQ` |
| D1.2 | Full | `mt_ebQURBOsM5`, `mt_c29FaCTNsx`, `mt_JEtvvsAQjQ` |
| D1.3 | Full | `mt_c29FaCTNsx`, `mt_VhBH8wrFC6`, `mt_mayItsxMUu` |
| D1.4 | Full | `mt_ryyJWULiP5` |
| D1.5 | Full | `mt_1VSfm9yiLn`, `mt_kxeuXm6EyC`, `mt_VhBH8wrFC6`, `mt_mayItsxMUu`, `mt_JEtvvsAQjQ` |
| D2 | Full | Child-expectation rollup |
| D2.1 | Full | `mt_iFFKZd-Vgv` |
| D2.2 | Full | `mt_gTI7MuS-y8`, `mt_ryyJWULiP5` |
| E1 | Full | Child-expectation rollup |
| E1.1 | Full | `mt_fEuoBYw6bU`, `mt_zuOGOGFAKb`, `mt_sBcRdUfAzV`, `mt_hRZyKvz1KN` |
| E1.2 | Full | `mt_MqqR7VUoz1`, `mt_6xNmQLzuqm` |
| E1.3 | Full | `mt_B1lPmwJz0h` |
| E1.4 | Full | `mt_61Pa4Eksva`, `mt_w4cUnN_SsQ` |
| E1.5 | Full | `mt_TdV9YGJEoY`, `mt_Y9XKzLrUAZ`, `mt_61Pa4Eksva` |
| E2 | Full | Child-expectation rollup |
| E2.1 | Full | `mt_cqSf213hSa`, `mt_e7tLi9SCIE`, `mt_jHv4BgRK8B` |
| E2.2 | Full | `mt_OzRZ89GrQW`, `mt_e4x3l2JeLI` |
| E2.3 | Full | `mt_e4x3l2JeLI` |
| E2.4 | Full | `mt__N55B7u7HD`, `mt_TcG90kS8nu`, `mt_2XDGT5tei1` |
| F1 | Full | Child-expectation rollup |
| F1.1 | Full | `mt_AF2BeFQwfX`, `mt_FIkqA0qhnj`, `mt_pbuhUQJjtt` |

The [machine-readable mapping](ontario-grade2-mathematics-mapping-2026-10-23.json) contains codes and official source links, without verbatim Ontario expectations.