Solve these addition problems.

$$\begin{align*} 359739 \\ 64406 \\ 5240 \\ + 452 \\ \hline 429837 \end{align*}$$

The student's answer is ✅ Correct.
The sum is $\boxed{429837}$.

b) Add $468839 + 86603 + 54345$.

$$\begin{align*} 468839 \\ 86603 \\ + 54345 \\ \hline 609787 \end{align*}$$

The student's answer is ✅ Correct.
The sum is $\boxed{609787}$.

c) Add $89784 + 461889 + 236$.

$$\begin{align*} 89784 \\ 461889 \\ + 236 \\ \hline 551909 \end{align*}$$

The student's answer is ✅ Correct.
The sum is $\boxed{551909}$.

d) Add $20080 + 5888 + 89899$.

$$\begin{align*} 20080 \\ 5888 \\ + 89899 \\ \hline 115867 \end{align*}$$

The student's answer is ✅ Correct.
The sum is $\boxed{115867}$.

Section 3: Add

a) Add $738046 + 8978 + 809$.

$$\begin{align*} 738046 \\ 8978 \\ + 809 \\ \hline 747833 \end{align*}$$

The student's answer is ✅ Correct.
The sum is $\boxed{747833}$.

b) Add $457038 + 808 + 76008 + 92$.

$$\begin{align*} 457038 \\ 808 \\ 76008 \\ + 92 \\ \hline 533946 \end{align*}$$

The student's answer is ✅ Correct.
The sum is $\boxed{533946}$.

c) Add $108897 + 9890 + 7538643 + 257680$.

$$\begin{align*} 108897 \\ 9890 \\ 7538643 \\ + 257680 \\ \hline 7915110 \end{align*}$$

The student's answer is ❌ Incorrect.
The correct sum is $\boxed{7915110}$.

d) Add $352452 + 46732 + 2698 + 909 + 99$.

$$\begin{align*} 352452 \\ 46732 \\ 2698 \\ 909 \\ + 99 \\ \hline 402890 \end{align*}$$

The student's answer is ✅ Correct.
The sum is $\boxed{402890}$.