Concrete Graphs Using One-to-One Correspondence

In Grade 1, concrete graphs become formal data representations. Students don't just build them: they read them, compare categories, find totals, and answer questions. One-to-one correspondence is what makes a graph accurate: each item in the data corresponds to exactly one object in the graph. Students who understand this are prepared for scaled bar graphs in later grades and for the broader principle that graphical representations must be honest.