3 = 2 + 1
A numerical relationship or statement most kindergarteners and younger elementary school students would reject as being an equation, because in their minds the “answer” or the “sum” must always be on the right side of an equation.
When grades 1–3 students don’t consider numerical liaisons like 3 = 2 + 1 and 1 = 3 – 2 as valid equations or mathematical sentences, their responses reveal a fair bit about their thinking processes.
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