CMAS math practice for Colorado grades 3 to 8

This is the spine of how we teach CMAS math. Every lesson ends with the child saying, in a sentence or two, why the answer is right, and at least once a week they critique a wrong solution we have written on purpose. That is SMP 3 practised directly, without copying a single test item.

Sources: CMAS Mathematics Frameworks for grades 3 to 8 via CMAS Test Design, and Fact Sheets and FAQs (scoring), CDE, read 31 October 2026.

What this means for home practice: a grade 4 child should do every problem by hand, and a grade 7 child should practise with a plain five-function calculator, not the graphing app on a phone. A grade 8 child who leans on graphing to solve systems of equations needs to be fluent with algebra by hand and a scientific calculator before April.

Sources: CMAS Calculator Policy (PDF), CDE, and the Colorado Practice Resources portal, both read 31 October 2026.

1. Grade 4 reasoning, our task. Jordan says 5/8 is greater than 3/4 “because 5 is bigger than 3”. Is Jordan correct? Explain with numbers or a model.
2. Step 1: decide before you calculate. Jordan compared numerators only. That works only when the pieces are the same size, and eighths and fourths are not.
3. Step 2: make the pieces match. 3/4 = 6/8, because each fourth splits into two eighths. Now both fractions count eighths.
4. Step 3: compare and answer the claim. 6/8 is more than 5/8, so 3/4 is greater. Jordan is not correct.
5. Step 4: name the flaw in one sentence. “Jordan compared the tops without checking that the pieces were the same size; eighths are smaller than fourths.” That sentence is what a reasoning rubric is looking for, and it is the step children leave out.

1. Grade 7 modeling, our task, five-function calculator allowed. A school garden bed is 12 feet long and 8 feet wide. Mulch should be 3 inches deep. One bag holds 2 cubic feet. How many bags should the class buy?
2. Model it. The mulch is a rectangular prism. 3 inches is 3/12 = 0.25 feet, so units match before multiplying.
3. Solve. 12 x 8 x 0.25 = 24 cubic feet. 24 / 2 = 12 bags.
4. Interpret. Exactly 12 bags covers it with nothing to spare. Some mulch always spills or settles, so a careful answer says 12 is the minimum and 13 gives a margin. Either answer earns credit only with the reason attached.
5. Check. A bed of 96 square feet at a quarter foot deep is a quarter of 96, which is 24. The estimate agrees.

The common thread is the last step. In the reasoning task, the child names the mistake; in the modeling task, the child says what the number means for the garden. CMAS gives those last steps their own subclaims, so we practise them as seriously as the arithmetic.

1. Early January 2027: find the weak subclaim. Look at last spring’s CMAS report or a school benchmark. If there is none, we run one short diagnostic of our own across the four subclaims in the first class.
2. January to February: repair content from the root. If A or B is weak, reteach the grade’s major clusters, and check last year’s too, since reasoning and modeling tasks lean on securely held prior-grade knowledge.
3. March: one explanation every lesson. Each session ends with a written reason, and once a week the child critiques a wrong solution. Modeling tasks get a fourth step: say what the answer means in the situation.
4. Late March: the real interface. Work through the TestNav tutorial and one grade-level practice set on the Colorado portal with the correct calculator rule and reference sheet. Score it with CDE’s scoring guide.
5. The week before April 5: rest and routine. Short mixed sets, no new topics, and a word about the three-minute pause so a tired child knows a break is allowed.