The Year 4 Subtract Two 4-Digit Numbers – One Exchange PowerPoint guides both teachers and children through the lesson, including use of the varied fluency, reasoning and problem solving, deeper reasoning and scaffolded resources. Key learning information about this step:
Key Vocabulary
exchange: When a digit is taken from one place value column and placed in another.
formal written method: This is also known as the column method for addition, subtraction and multiplication. For division, this may also be known as the bus stop method.
place value chart: Used to identify the value of the digits that make up a number.
placeholder: 0 is used to hold a place in a number and maintain its place value.
Varied Fluency
Knowledge Organiser
• Designed to support all children via key information and examples.
Scaffolded Examples
• Subtracting with counters and sentence stems; exchanging using the formal written method with the digits lined up and the exchange shown.
Support
• Q1: Subtract two 4-digit numbers using counters; both numbers and the exchange are given.
• Q2: Complete two column subtractions; the digits are written in the grids.
• Q3: Solve a word problem; the numbers are written in the grid.
Core
• Q1: Subtract from a number shown in counters; write the first number, the exchange and the answer in the grid.
• Q2: Transfer two linear subtractions into blank grids; one has a 3-digit number.
• Q3: Solve a word problem using a blank grid.
Stretch
• Q1: Draw the counters, then show the exchange and record the subtraction.
• Q2: Line up the digits; the exchange comes from the tens, the hundreds or the thousands.
• Q3: Solve a two-part word problem; both parts need an exchange.
Reasoning and Problem Solving
Support
• Q1: Reasoning - judge a character’s statement about an exchange; the first number is shown in counters.
• Q2: Reasoning - compare place value counters with the formal written method for the same subtraction; a tip is given.
• Q3: Problem Solving - build a subtraction with a given answer and one exchange from the tens column; a starting example is given.
Core
• Q1: Reasoning - judge a character’s statement about an exchange.
• Q2: Reasoning - compare place value counters with the formal written method for the same subtraction.
• Q3: Problem Solving - build a subtraction with a given answer and exactly one exchange.
Stretch
• Q1: Reasoning - judge a character’s statement where the exchange comes from the hundreds or thousands.
• Q2: Reasoning - compare place value counters with the formal written method for the same subtraction where the first number has a 0 or the second number has 3 digits.
• Q3: Problem Solving - build a subtraction with a given answer where the exchange is not from the tens column.
Deeper Reasoning
The questions in this set focus on problem solving with subtraction to deepen understanding in subtracting numbers with up to four digits using the formal written methods of columnar subtraction where appropriate, and solving subtraction two-step problems in contexts, deciding which operations and methods to use and why.
