Add a two-digit and a one-digit number - with regrouping

Learning Objectives Define 'regrouping' in the context of addition. Identify when regrouping is necessary in addition problems. Apply the standard algorithm for adding two-digit and one-digit numbers with regrouping. Accurately perform addition of two-digit and one-digit numbers involving regrouping. Explain the process of carrying over tens when the sum of the ones place exceeds nine. Solve real-world problems requiring the addition of two-digit and one-digit numbers with regrouping. Ever wonder how stores calculate your total bill quickly when you buy a few small items? 🛒 It often involves adding numbers, sometimes with a special trick called 'regrouping'! In this lesson, you'll master the skill of adding a two-digit number and a one-digit number...

TermDefinitionExample Two-Digit NumberA whole number that has a tens place and a ones place (e.g., 23, 78).In the number 47, '4' is in the tens place and '7' is in the ones place. One-Digit NumberA whole number that has only a ones place (e.g., 5, 9).The number 6 is a one-digit number. Place ValueThe value of a digit based on its position in a number (e.g., ones, tens, hundreds).In 52, the digit '5' has a place value of 50 (5 tens), and '2' has a place value of 2 (2 ones). AdditionThe mathematical operation of combining two or more numbers to find their total sum.3 + 5 = 8, where 8 is the sum. Regrouping (Carrying Over)The process in addition where 10 units of a lower place value are converted into 1 unit of the next higher place value (e.g., 10 one...

Place Value Alignment Rule $ \begin{array}{r} \text{Tens} & \text{Ones} \\ A & B \\ + & C \\ \hline \end{array} $ Before adding, always write the numbers one above the other, ensuring the ones digits are aligned vertically and the tens digits are aligned vertically. This ensures you add digits of the same place value. Ones Place Addition and Regrouping Rule If $B + C \ge 10$, then $B + C = 10 \times (\text{carry}) + (\text{ones digit})$. Start by adding the digits in the ones column. If their sum is 10 or greater, write the ones digit of the sum in the ones column of the answer and 'carry over' the tens digit (which is 1) to the tens column. Tens Place Addition Rule $\text{Tens Sum} = A + \text{carried over ten(s)}$ After handling the ones place...