Solve the following addition problems: b. 52 + 26 = c. 46 + 25 =

Add the ones place: $2 + 8 = 10$. Write 0, carry 1.

\begin{array}{r@{}r@{}r} & 5 & 2 \\ + & 2 & 8 \\ \hline & & 0 \end{array}

Add the tens place: $5 + 2 + 1 = 8$.

\begin{array}{r@{}r@{}r} & 5 & 2 \\ + & 2 & 8 \\ \hline & 8 & 0 \end{array}

So, $52 + 28 = 80$.

80

Subtract: $\text{lb} = 70 - 50$.

$70 - 50 = 20$.

So, $\text{lb} = 20$ lb.

Add the ones place: $0 + 5 = 5$.

Add the tens place: $2 + 2 = 4$.

\begin{array}{r@{}r@{}r} & 2 & 0 \\ + & 2 & 5 \\ \hline & 4 & 5 \end{array}

So, $20 + 25 = 45$ lb.

45 lb