# Flexible multiplicative strategies - multi digit numbers

This resource has been developed in partnership with the NSW Mathematics Strategy Professional Learning team, Curriculum Early Years and Primary Learners, and Literacy and Numeracy.

## Using the resource

This resource is the third section of a four part resource supporting flexible multiplicative thinking. Use this resource in conjunction with the other resources in this series in order to support a connected network of critical mathematical concepts, skills and understanding.

### Task 1: Doubling and halving 2-digit numbers

Students double and half 2-digit numbers through visualising and using manipulatives.

Students explore ways of thinking and develop fluency when doubling.

### Task 3: Making landmark numbers: renaming for multiplication

Students understand the connection between strategies.

### Task 4: Understanding the area method

Students use the area method of multiplication.

### Task 5: If I know…

Students build number sense using the relationships between numbers and operations.

Students use known facts to make problems easier to solve.

### Task 7: Investigating more factors

Students manipulate numbers to make problems easier to solve.

### Task 8: Using related facts

Students use related facts to flexibly solve division and multiplication problems.

From Marilyn Burns, About Teaching Mathematics, 2015

Students watch the Leftovers video then explore remainders and fair share situations.

### Task 10: How many ways can they be related?

Students develop efficient mental computation and strong number sense.

### Task 11: Patterns of divisibility

Students investigate, notice and test generalisations and how useful they are in solving division problems.

### Task 12: Dividing by partitioning the dividend (using the distributive property)

Students explore the concept of the distributive property.

Students use factorising to solve problems.

Students think flexibly and strategically about the order solving multiplicative involving multiple factors.

### Task 15: Dividing by factorising

Students explore the concept of dividing by factorising.

Students explore ways they use estimation to determine the reasonableness of multiplicative solutions.

### Task 17: What’s in a remainder?

Students understand remainders and fair share situations.

### Task 18: Divide me this

Students understand factor-factor-product relationships and operating with division.

Students critique different strategies and problem situations.

Students develop fluency with multiplicative situations.

### Task 21: Investigating written methods for multiplication

Students explore and make sense of written multiplication methods.

### Task 22: Investigating written methods of division

Students explore and make sense of written division methods.

### Task 23: Doubling and halving-a number talk

Students watch the Doubling and halving – a number talk video then explore the relationship between doubling and halving.

### Task 24: Let’s investigate 2 - 15 x 9

Students watch the Let’s investigate 2 – 15 x 9 video then think about efficiency in representing multiplicative situations.

Students watch the Fewest squares - part 1 video, Fewest squares – part 2 video and Fewest squares - part 3 video to explore and make sense of square numbers.

### Task 26: Jump! What if?

Students watch the Jump! What if? – part 1 video and Jump! What if? – part 2 video to think multiplicatively about ‘times as many’ scenarios.

From NRICH maths

Students watch the Super shapes video then solve multiplicative problems where the product is known.

### Task 28: Colour in fractions

Students watch the Colour in fractions video then explore equivalence in the context of fractions.