The Year 3 Add and Subtract 100s 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.
place value counters: A physical resource which represents numbers. They are usually in different colours and have different numbers written on them, to represent ‘ones’, ‘tens’, ‘hundreds’ etc.
placeholder: 0 is used to hold a place in a number and maintain its place value.
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.
Varied Fluency
Knowledge Organiser
• Designed to support all children via key information and examples.
For the purple sections of the four levels, copy and paste these from the first sheet of the varied fluency resource.
Scaffolded Examples
• Scaffolded example of adding and subtracting 100s using a place value chart and function machine.
Support
• Q1: Adding or subtracting 100s from a number in a place value chart, with related number facts.
• Q2: Finding both numbers out of a function machine; one is partially completed.
• Q3: Using a number fact within 10 to add or subtract 100s; place value counters provided.
Core
• Q1: Adding and subtracting 100s from a number in a place value chart.
• Q2: Finding both numbers out of a function machine.
• Q3: Using a number fact within 10 to add or subtract 100s.
Stretch
• Q1: Adding and subtracting 100s, including missing starting numbers.
• Q2: Working backwards from one output to find the input and the other output.
• Q3: Using a number fact within 10 to add or subtract 100s and its inverse.
Reasoning and Problem Solving
Support
• Q1: Reasoning - judging whether a character has changed the correct column when adding or subtracting 100s from a 3-digit number; place value chart included.
• Q2: Reasoning - finding the odd one out from three calculations adding or subtracting 100s; Base 10 provided for starting number.
• Q3: Problem Solving - adding or subtracting a multiple of 100 so that the answer fits one condition.
Core
• Q1: Reasoning - judging whether a character has changed the correct column when subtracting 100s from a 3-digit number.
• Q2: Reasoning - finding the odd one out from three calculations adding or subtracting 100s.
• Q3: Problem Solving - adding or subtracting a multiple of 100 so that the answer fits two conditions.
Stretch
• Q1: Reasoning - judging if the calculations are correct where a subtraction leaves 0 hundreds, and an addition with a 2-digit number.
• Q2: Reasoning - finding the odd one out; numbers in numerals and words.
• Q3: Problem Solving - two-step chains adding and subtracting different multiples of 100 to reach a target.
Deeper Reasoning
The question in this set focuses on investigating the possible combinations of animals a farmer could buy and sell at a market and playing a dice game with a partner to deepen understanding in adding and subtracting numbers mentally, including three-digit numbers and hundreds.
