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# Number & Operations in Base Ten

#### Use place value understanding and properties of operations to add and subtract.

In the early grades, students begin to understand numbers, ways of representing numbers, relationships among numbers, and number systems.  NCTM states, “It is absolutely essential that students develop a solid understanding of the base-ten numeration system and place-value concepts by the end of grade 2.” For students to develop this understanding they need many and various experiences with how numbers are written and with concrete models, such as base-ten materials, to group and ungroup by tens and to make fair trades. Counting within 1000 and skip counting by tens are more deeply developed through the use of manipulatives, frames, and the hundreds chart – expanded beyond 100. Understanding the base-ten system aids students as they add and subtract within 1000, as they develop mental fluency with addition and subtraction, and as they make comparisons of numbers and the quantities they represent.

This continuum contains Counting and Cardinality standards for K, Number and Operations and Algebraic Thinking standards K-3, Number and Operations in Base Ten standards K-3, Number and Operations – Fractions standards for grade 3.