Reasoning · Grade 2-1 Classification and Criteria
Problem
Counting horns on the drawn faces, the columns run 1, 2, 3.
Counting the horns on the faces already drawn tells us what each column is collecting, and the count grows by one each step.
K.MD.B.3Look For A PatternThe face sitting in the middle row is square, so the rows run ○, □, ▽.
Each row holds one face shape; the shape already drawn in that row tells us the row's label.
K.MD.B.3Organize Information In More WaysMatching each row shape to each column count fixes all nine cells.
Once both labels for a cell are known, exactly one kind of face fits, so each empty cell has one correct drawing.
2.G.A.1Draw A DiagramOnce a cell's row label and column label are both known, exactly one kind of face belongs there.
The table pairs each face shape with each horn count independently, so a cell is one shape choice together with one horn choice and nothing else.
With both labels fixed, every face that disagrees with either label is ruled out, and only one candidate is left standing.
A two-way table lets you sort by two things at the same time — once you know the row and the column, the picture in the box is decided!