standard_description: Fluently add and subtract within 1000 using strategies and algorithms based on place value, properties of operations, and/or the relationship between addition and subtraction.
problem_activity: Solve. Show or explain your work.
a.
$$\begin{align} 7,396 \\ {–\ 2,145}& \\ \hline \end{align}$$
b.
$$87,625-5,031=$$
______
c.
$$\begin{array}{r} &19,850\\ -\!\!\!\!\!\!&15,761\\ \hline \end{array}$$


aligns: no