\( \definecolor{colordef}{RGB}{249,49,84} \definecolor{colorprop}{RGB}{18,102,241} \)
$$\begin{aligned}[t]2\text{ tens }+ \textcolor{colorprop}{15\text{ ones }} &= 2\text{ tens }+ \textcolor{colorprop}{1\text{ ten }+ 5\text{ ones }}\\ 2\text{ tens }+ 15\text{ ones } &= 3\text{ tens }+ 5\text{ ones }\\ \end{aligned}$$
\(\quad+ \quad \)\(\quad =\quad\)