Grade 1: 43 skills.

Indented means “needs the one above it first”. A skill with no indent starts from earlier grades.

A ten as a bundle of ten ones CCSS-M 1.NBT.2a
Adding by counting everything
- Order doesn't change a sum CCSS-M 1.OA.3
  
  Misconceptions recognised: counting on from the start number itself.
  - Adding three numbers CCSS-M 1.OA.2
- Subtracting by counting back
  
  Misconceptions recognised: counting back and landing one off.
  - Making ten to add CCSS-M 1.OA.6
    
    Misconceptions recognised: rounding to add, then forgetting to adjust.
    - Two-digit plus one-digit, carrying CCSS-M 1.NBT.4
      
      Misconceptions recognised: forgetting the carried ten.
  - Subtracting tens from tens CCSS-M 1.NBT.6
  - Subtracting through ten CCSS-M 1.OA.6
  - Two-digit plus one-digit
    
    Misconceptions recognised: adding the one-digit number to the tens.
Building shapes from shapes CCSS-M 1.G.2
Coins to 50¢ Ontario F1
Counting on from any number CCSS-M 1.NBT.1
- Adding by counting on CCSS-M 1.OA.5-6
  
  Misconceptions recognised: counting on from the start number itself.
  - Adding within 20 CCSS-M 1.OA.6
    - Subtracting within 20
      
      Misconceptions recognised: subtracting each column on its own.
      - Stories: finding the result CCSS-M 1.OA.1
  - Doubles (4+4, 7+7) CCSS-M 1.OA.6
  - Subtracting by adding up CCSS-M 1.OA.4
    - Finding the missing number CCSS-M 1.OA.8
      
      Misconceptions recognised: adding every number on both sides.
      - Stories: finding the change
        
        Misconceptions recognised: operating on the given numbers instead of balancing.
        
        Stories: finding the start CCSS-M 1.OA.1
        
        Misconceptions recognised: operating on the given numbers instead of balancing.
    - Stories: comparing amounts
      
      Misconceptions recognised: the answer is the bigger number; choosing the operation from a keyword.
  - What the equals sign means CCSS-M 1.OA.7
    
    Misconceptions recognised: treating the equals sign as "the answer comes next".
- Counting to 120 CCSS-M 1.NBT.1
  - Reading & writing numbers to 120
    
    Misconceptions recognised: writing teens backwards (31 for thirteen); writing numbers as they sound (10023 for 123).
  - Skip counting by 2s
  - Skip counting by 5s
- Halves & quarters CCSS-M 1.G.3
Extending repeating patterns Ontario C1

Misconceptions recognised: a repeating unit that's one too long; the repeating unit backwards; a repeating unit that's one too short.
Measuring by repeating a unit CCSS-M 1.MD.2
- Comparing lengths through a third CCSS-M 1.MD.1
Shapes by their features CCSS-M 1.G.1

Misconceptions recognised: only the textbook orientation counts as the shape.
Skip counting by 10s Ontario B1
- Adding tens to a two-digit number CCSS-M 1.NBT.4 (part)
- Naming the tens (10, 20, 30…) CCSS-M 1.NBT.2c
  - Tens & ones in two-digit numbers CCSS-M 1.NBT.2
    
    Misconceptions recognised: writing expanded form by sticking the parts together; a digit's value is its face value.
    - Comparing two-digit numbers CCSS-M 1.NBT.3
      
      Misconceptions recognised: comparing numbers by the ones digit first.
    - Ten more, ten less CCSS-M 1.NBT.5
      
      Misconceptions recognised: ten more changes the ones digit.
Sorting & counting categories CCSS-M 1.MD.4

Misconceptions recognised: forgetting what's in both sets; counting only the overlap.
Talking about likely & unlikely Ontario D2
Telling time to the hour CCSS-M 1.MD.3
- Telling time to the half hour

Misconceptions are the rules children reach for that almost work; the names here are the research vocabulary for them. Cardinal Math watches for them as the problem is worked, not just in the answer. The guides under Help for parents walk through the common ones with examples.