Synthesizing addition and subtraction strategies to solve multi-step word problems.

Developing strategies to subtract from numbers with zeros in the tens or ones place.

Applying place value understanding to subtract when a hundred must be decomposed into tens.

Visualizing the decomposition of a ten into ten ones during subtraction using base-ten drawings.

Using addition to solve subtraction by finding the difference between two numbers on a number line.

Subtracting 2-digit and 3-digit numbers by jumping back on an open number line.

Practicing addition with regrouping tens into a hundred using base-ten diagrams and place value charts.

Using base-ten representations to visualize regrouping ones into a ten during addition.

Using open number lines to add 3-digit numbers by making jumps of hundreds, tens, and ones.

Introduction to addition within 1000 using expanded form to emphasize the value of each digit.