# Unit Overview: Addition and subtraction

## Lessons:

15 lessons

### 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.

• 1 Quiz
• 13m Video
• Presentation(PPT)
• Worksheet
• Transcript

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

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.

• 2 Quizzes
• 13m Video
• Presentation(PPT)
• Worksheet
• Transcript

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

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.

• 2 Quizzes
• 10m Video
• Presentation(PPT)
• Worksheet
• Transcript

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

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.

• 2 Quizzes
• 14m Video
• Presentation(PPT)
• Worksheet
• Transcript

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

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

• 2 Quizzes
• 12m Video
• Presentation(PPT)
• Worksheet
• Transcript

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

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

• 2 Quizzes
• 12m Video
• Presentation(PPT)
• Worksheet
• Transcript

### Applying rounding for estimating (adding)

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.

• 2 Quizzes
• 17m Video
• Presentation(PPT)
• Worksheet
• Transcript

### Applying rounding for estimating (subtracting)

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.

• 2 Quizzes
• 16m Video
• Presentation(PPT)
• Worksheet
• Transcript

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

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

• 2 Quizzes
• 17m Video
• Presentation(PPT)
• Worksheet
• Transcript

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

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

• 2 Quizzes
• 17m Video
• Presentation(PPT)
• Worksheet
• Transcript

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

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

• 2 Quizzes
• 17m Video
• Presentation(PPT)
• Worksheet
• Transcript

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

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

• 2 Quizzes
• 14m Video
• Presentation(PPT)
• Worksheet
• Transcript

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

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

• 2 Quizzes
• 24m Video
• Presentation(PPT)
• Worksheet
• Transcript

### Solving addition and subtraction word problems

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

• 2 Quizzes
• 19m Video
• Presentation(PPT)
• Worksheet
• Transcript

### Solving word problems with unknown values

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

• 2 Quizzes
• 17m Video
• Presentation(PPT)
• Worksheet
• Transcript