Students extend their understanding and strategies for adding and subtracting to solve problems involving multidigit numbers. Students apply place-value properties and use mental math strategies to calculate and estimate differences. Students also learn to use paper-and-pencil strategies (e.g., standard algorithm, expanded form) that apply place value concepts to add and subtract.

EXPECTATIONS
	Use this list of Expectations to assess students on the key concepts and skills in this unit.
E1*	Use and apply place value concepts to make connections among representations of multidigit numbers using base-ten pieces, number lines, expanded form, and standard form.
E2	Compose and decompose numbers using ones, tens, hundreds, and thousands.
E3	Show and recognize different partitions of multidigit numbers using different representations (e.g., base-ten pieces, number lines, number sentences).
E4	Compare and order multidigit numbers using base-ten pieces, number lines, and symbols (e.g., <, >, =).
E5*	Represent addition and subtraction problems using base-ten pieces and number lines.
E6*	Add and subtract multidigit numbers using mental math strategies (e.g., composing and decomposing numbers, counting) with base-ten pieces and number lines.
E7*	Add and subtract multidigit numbers using paper-and-pencil methods (e.g., expanded form, all-partials, compact).
E8	Estimate sums and differences using mental math strategies (e.g., rounding using benchmarks, using friendly numbers, composing and decomposing numbers, counting).
E9*	Demonstrate fluency with the subtraction facts related to the addition facts in Group F (14 − 4, 14 − 6, 14 − 8, 14 − 10, 15 − 5, 15 − 6, 15 − 9, 15 − 10, 16 − 6, 16 − 7, 16 − 9, 16 − 10, 17 − 7, 17 − 8, 17 − 9, 17 − 10, 18 − 8, 18 − 9, 18 − 10).
E10*	Determine the unknown number in an addition or subtraction sentence relating three whole numbers for the facts in Group F.
	* Denotes Benchmark Expectation