Regrouping from Tens to Hundreds

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If the sum in your tens column (including any carried digit) is $15$, what do you do?

You write the $5$ in the tens place of the answer and carry the $1$ to the hundreds column.

When you have $10$ tens, what do you regroup them as?

$10$ tens are regrouped as $1$ hundred.

$$490 + 290 = ?$$

$$\begin{array}{rr} & 490 \\ + & 290 \\ \hline & 780 \end{array}$$Ones: $0+0=0$. Tens: $9+9=18$. Write $8$, carry $1$. Hundreds: $1+4+2=7$.

$$265 + 81 = ?$$

$$\begin{array}{rr} & 265 \\ + & 81 \\ \hline & 346 \end{array}$$Ones: $5+1=6$. Tens: $6+8=14$. Write $4$, carry $1$. Hundreds: $1+2=3$.

$$583 + 142 = ?$$

$$\begin{array}{rr} & 583 \\ + & 142 \\ \hline & 725 \end{array}$$Ones: $3+2=5$. Tens: $8+4=12$. Write $2$, carry $1$. Hundreds: $1+5+1=7$.

$$351 + 451 = ?$$

$$\begin{array}{rr} & 351 \\ + & 451 \\ \hline & 802 \end{array}$$Ones: $1+1=2$. Tens: $5+5=10$. Write $0$, carry $1$. Hundreds: $1+3+4=8$.

When you carry from the tens place, what place value does the carried digit represent?

It represents hundreds.

In the problem $371 + 164$, what is the sum of the digits in the tens column ($7+6$)?

$13$. Because it's the tens column, this represents $13$ tens, or $130$.

When the tens column adds up to $13$ (tens), what do you do?

1. Write the $3$ in the tens place of the answer. 2. Carry the $1$ (which represents one hundred) to the top of the hundreds column.

$$371 + 164 = ?$$

$$\begin{array}{rr} & 371 \\ + & 164 \\ \hline & 535 \end{array}$$Ones: $1+4=5$. Tens: $7+6=13$. Write $3$, carry $1$. Hundreds: $1+3+1=5$.

$$182 + 253 = ?$$

$$\begin{array}{rr} & 182 \\ + & 253 \\ \hline & 435 \end{array}$$Ones: $2+3=5$. Tens: $8+5=13$. Write $3$, carry $1$. Hundreds: $1+1+2=4$.