The Year 3 Subtract Two Numbers (across a 10) 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
place value chart: Used to identify the value of the digits that make up a number.
Base 10: A physical resource which represents numbers. The small cubes represent ‘ones’; the rods represent ‘tens’ and are made up of 10 small cubes; the squares represent ‘hundreds’ and are made up of 10 rods; the large cubes represent ‘thousands’ and are made up of 10 squares.
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.
Varied Fluency
Knowledge Organiser
• Designed to support all children via key information and examples.
Scaffolded Examples
• Using Base 10 and sentence stems to subtract two 2-digit numbers with an exchange.
Support
• Q1: Use Base 10 to complete the subtraction; sentence stems are given.
• Q2: Complete two column subtractions; the exchange is given.
• Q3: Find one missing digit in a column subtraction; the exchange is given.
Core
• Q1: Use Base 10 to complete the subtraction.
• Q2: Complete two column subtractions; no exchange is given.
• Q3: Find one missing digit in a column subtraction.
Stretch
• Q1: Draw the Base 10 for a 2-digit number, then show the exchange.
• Q2: Place the digits in the grid and complete the subtractions.
• Q3: Find two missing digits in a column subtraction.
Reasoning and Problem Solving
Support
• Q1: Reasoning – judge whether a character has exchanged correctly when subtracting two 3-digit numbers; place value chart with Base 10 provided.
• Q2: Reasoning – explain if a statement is correct about two column subtractions.
• Q3: Problem Solving – find missing ones digits that make a 3-digit subtraction need an exchange; exchange given.
Core
• Q1: Reasoning – judge whether a character has exchanged correctly when subtracting two 3-digit numbers.
• Q2: Reasoning – explain if a statement is correct about three subtractions.
• Q3: Problem Solving – find missing ones digits that make a 3-digit subtraction need an exchange.
Stretch
• Q1: Reasoning – judge whether a character has correctly identified the missing digits in a subtraction.
• Q2: Reasoning – explain if a statement is correct about three subtractions; numbers given as numerals and as words.
• Q3: Problem Solving – find missing tens and ones digits that keep a 3-digit subtraction to only one exchange.
Deeper Reasoning
The questions in this set focuses on identifying the missing digits in a calculation to deepen understanding in subtracting numbers with up to three digits, using formal written methods of columnar subtraction.
