Learn the crucial concept of regrouping, also known as 'carrying.' This stack focuses specifically on what to do when the sum in the ones column is 10 or more.
When the sum of a column is \(10\) or more, you bundle a group of \(10\) and move it as a '1' to the next higher place value column.
What is another word for 'regrouping'?
A common word is 'carrying' or 'carrying over'.
In the problem \(28 + 15\), what is the sum of the digits in the ones column (\(8+5\))?
The sum is \(13\).
When the ones column adds up to \(13\), what two things do you do?
1. Write the \(3\) (from the ones place of \(13\)) in the answer's ones place.
2. Carry the \(1\) (from the tens place of \(13\)) to the top of the tens column.
$$28 + 15 = ?$$
$$\begin{array}{rr} & 28 \\ + & 15 \\ \hline & 43 \end{array}$$Ones: \(8+5=13\). Write \(3\), carry \(1\) to the tens column.
Tens: Add the carried \(1\) to the other tens: \(1+2+1=4\).
