# Flexible additive strategies - 3 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 additive 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.

Students use the cumulative total of dice rolls to reach 360.

### Task 2: 4 turns to 1000

Students use the cumulative total of playing cards to reach 1000.

• Variation 1: Teacher models the game

• Variation 2: Students develop a strategy that increases their chance of winning

### Task 4: Subtraction face off: hundreds, tens and ones

Students use an Explanation spinner and share the strategies used to work out differences.

Students estimate and determine which problems would be approximately equivalent to 250.

### Task 6: How many ways can they be related?

Students are provided with a string of numbers and consider how they could move from one number to the next, using any operation.

Students use a calculator to ‘wipe’ a digit from a three-digit number

• Variation 1: Increase numbers beyond 999

• Variation 2: Investigate what happens when you want to wipe out a ‘0’

• Variation 3: Use decimal numbers

• Variation 4: Use negative numbers

### Task 8: Hit the target

Students use playing cards to reach a three-digit target number.

• Variation 1: Students keep a cumulative total of the difference between their total and the target

• Variation 2: Change the target each round

• Variation 3: Make the target a four-digit number

Students use playing cards assigned different decimal values (for example, clubs and hearts are worth tenths) and add or subtract to reach the target number.

• Variation 1: Remove picture cards and play with cards Ace-10 only
• Variation 2: Students invent extra rules for playing
• Variation 3: Change the winning score
• Variation 4: Highest score after five turns wins

### Task 10: Let’s talk 1

Students watch ‘Let’s talk 1’ .