Subtract a one-digit number from a two-digit number - with regrouping

Learning Objectives Identify when regrouping is necessary in subtraction problems. Explain the concept of regrouping (borrowing) from the tens place to the ones place. Accurately perform subtraction of a one-digit number from a two-digit number using the standard algorithm with regrouping. Solve subtraction problems involving regrouping in the ones place with confidence. Verify subtraction answers using addition. Apply subtraction with regrouping to solve real-world problems. Ever tried to buy something for $23 but only had $7 in your pocket? 💸 How much more do you need? This lesson will show you how to figure that out! In this lesson, you'll master subtracting a small number from a larger one, especially when the 'ones' digit of the larger number is too sma...

TermDefinitionExample RegroupingThe process of exchanging one unit from a higher place value for ten units of the next lower place value (e.g., 1 ten for 10 ones) to allow subtraction when the top digit in a column is smaller than the bottom digit.To subtract 7 from 32, we 'regroup' 1 ten from the 3 tens, leaving 2 tens, and add 10 ones to the 2 ones, making it 12 ones. Place ValueThe value of a digit based on its position in a number. For example, in the number 45, the '4' is in the tens place and the '5' is in the ones place.In the number 63, the digit '6' has a value of 60 (6 tens), and the digit '3' has a value of 3 (3 ones). MinuendThe number from which another number is subtracted. It is typically the larger number in a subtraction p...

Standard Subtraction Algorithm (Vertical Alignment) 1. Write the minuend above the subtrahend, aligning digits by their place value (ones under ones, tens under tens). 2. Start subtracting from the ones column. This rule ensures that you are subtracting digits of the same place value from each other, which is fundamental for accurate calculation. Proper alignment prevents common errors. Regrouping Rule for Ones Place If the digit in the ones place of the minuend ($A$) is smaller than the digit in the ones place of the subtrahend ($B$), i.e., $A < B$: 1. Decrease the tens digit of the minuend by 1. 2. Increase the ones digit of the minuend by 10. This rule explains how to perform regrouping when you cannot directly subtract in the ones column. You 'borrow' a ten...