standard_description: Compose and decompose numbers from 11 to 19 into ten ones and some further ones, e.g., by using objects or drawings, and record each composition or decomposition by a drawing or equation (e.g., 18 = 10 + 8); understand that these numbers are composed of ten ones and one, two, three, four, five, six, seven, eight, or nine ones.
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