### Adding and subtracting 1-digit numbers to/from 3-digit numbers

In this lesson, we will investigate different mental strategies to add and subtract, including regrouping.

Skip navigation# Unit Overview: Addition and subtraction

## Lessons:

### Adding and subtracting 1-digit numbers to/from 3-digit numbers

### Adding multiples of 10 to 3-digit numbers

### Subtracting multiples of 10 from 3-digit numbers

### Adding and subtracting multiples of 100 to/from 3-digit numbers

### Adding two 3-digit numbers (without regrouping)

### Subtracting two 3-digit numbers (without regrouping)

### Applying rounding for estimating (adding)

### Applying rounding for estimating (subtracting)

### Adding two 3-digit numbers (regrouping in one column)

### Adding two 3-digit numbers (regrouping in multiple columns)

### Subtracting 3-digit numbers (regrouping tens to ones)

### Subtracting 3-digit numbers (regrouping hundreds to tens)

### Subtracting 3-digit numbers (regrouping in multiple columns)

### Solving addition and subtraction word problems

### Solving word problems with unknown values

15 lessons

In this lesson, we will investigate different mental strategies to add and subtract, including regrouping.

In this lesson, we will use known number facts in order to mentally add multiples of 10 to 3-digit numbers. We will look at partitioning strategies and analyse place value to make mental addition more efficient.

In this lesson, we will use known number facts in order to mentally subtract multiples of 10 from 3-digit numbers. We will look at partitioning strategies and analyse place value to make mental subtraction more efficient.

In this lesson, we will use known number facts in order to mentally add and subtract multiples of 100 to and from 3-digit numbers. We will look at partitioning strategies and analyse place value to make mental addition and subtraction more efficient.

In this lesson, we will learn to partition 3-digit numbers in order to mentally add them accurately.

In this lesson, we will learn to partition 3-digit numbers in order to mentally subtract them accurately.

In this lesson, we will build on our knowledge of the 10 times table in order to estimate by rounding. We will do this to answer addition questions.

In this lesson, we will build on our knowledge of the 10 times table in order to estimate by rounding. We will do this to answer subtraction questions.

In this lesson, we will build on our knowledge of partitioning and estimating and introduce column addition.

In this lesson, we will look at using column addition when a number requires regrouping in more than one column when adding.

In this lesson, we will build on our knowledge of column addition and introduce regrouping for column subtraction.

In this lesson, we will focus on column subtraction where regrouping from the hundreds into the tens column is needed.

In this lesson, we will consolidate learning on column subtraction and will practise regrouping across all columns

In this lesson, we will consolidate learning on column addition and subtraction by applying this knowledge to word problems.

In this lesson, we will answer addition and subtraction word problems which require us to identify the unknown quantity.

Units in Maths

- Number sense and exploring calculation strategies
- Place value
- Graphs
- Addition and subtraction
- Length and perimeter
- Multiplication and division
- Deriving multiplication and division facts
- Time
- Fractions
- Angles and shape
- Measures
- Securing multiplication and division
- Exploring calculation strategies and place value
- Fractions: parts and wholes
- Reasoning with 4-digit numbers
- Addition and subtraction
- Multiplication and division
- Interpreting and presenting data
- Securing multiplication facts
- Fractions
- Time
- Decimals
- Area and perimeter
- Solving measure and money problems
- 2-D Shape and Symmetry
- Position and Direction
- Reasoning with patterns and sequences
- 3D Shape
- Working with fractions
- Taking fractions further
- Reasoning with large whole numbers
- Problem solving with integer addition and subtraction
- Line graphs and timetables
- Multiplication and division
- 2-D shape, perimeter and area
- Fractions and decimals
- Angles
- Fractions, decimals and percentages
- Transformations
- Converting units of measure
- Calculating with whole numbers and decimals
- 2-D and 3-D shape
- Volume
- Problem solving with whole numbers and decimals
- Equivalent fractions
- Integers & Decimals
- Multiplication and division
- Calculation problems
- Fractions
- Missing angles and lengths
- Coordinates and shape
- Fractions
- Decimals and measures
- Percentages and statistics
- Proportion problems
- Extending calculation strategies and additive reasoning

- Doubling and halving
- Addition and subtraction within 10
- Exploring calculation strategies within 20
- Money
- Measures
- 2-D shape, perimeter and area
- Numbers to 50
- Manipulating and calculating with fractions
- Fractions
- Fractions and decimals
- Conceptualising and comparing fractions
- Numbers 50 to 100 and beyond
- Reasoning with large whole numbers
- Converting units of measure
- Numbers to 10
- Solving measure and money problems
- Addition and subtraction within 20
- Addition and subtraction (applying strategies)
- Numbers within 1000
- Place value
- Problem solving with integer addition and subtraction
- Volume
- Positive and negative numbers
- Numbers within 10
- Numbers within 15
- Addition and subtraction within 20
- Measures (1): Length and mass
- Measures (2): Capacity and volume
- Addition and subtraction of 2-digit numbers
- Fractions
- Multiplication and division
- Multiplication and division
- Axioms and arrays
- Prime factor decomposition
- Indices and standard form
- Time
- Addition and subtraction of 2-digit numbers (regrouping and adjusting)
- Area and perimeter
- Numbers and numerals
- Percentages
- Fractions
- Measures: Length
- Numbers beyond 20
- Time
- Securing multiplication facts
- Addition and subtraction within 10
- Measures: Mass
- Number sense and exploring calculation strategies
- Addition and subtraction
- Securing multiplication and division
- Position and Direction
- Pattern and Early Number
- Addition and subtraction word problems
- Fractions
- Decimals
- Multiplication and division: 3 and 4
- Multiplication and division: 2, 5 and 10
- Measures: Capacity and volume
- Addition and subtraction
- Extending calculation strategies and additive reasoning
- Deriving multiplication and division facts
- Calculating with whole numbers and decimals
- Integers & Decimals
- Multiplication and division
- Grouping and Sharing
- Surds and trigonometry
- Numbers within 6
- Numbers within 100
- Exploring calculation strategies
- Time
- Exploring calculation strategies and place value
- Multiplication and division
- Factors and multiples
- Graphs
- Graphs
- Reasoning with 4-digit numbers
- Reasoning with patterns and sequences
- Calculation problems
- Numbers within 20
- Money
- Multiplication and division
- Fractions, decimals and percentages
- Decimals and measures
- Early Mathematical Experiences
- Order of operations
- Depth of numbers within 20
- Numbers to 20
- Addition and subtraction within 20 (comparison)
- Addition and subtraction within 6
- Accuracy and estimation
- Money
- Length and perimeter
- Fractions
- Fractions
- Problem solving with whole numbers and decimals