teaching resource

Addition Detectives PowerPoint

Updated: 22 Jun 2023

An engaging 43-slide PowerPoint styled as a detective story in which students are tasked with using different addition strategies to uncover suspects.

Editable: PowerPoint
Pages: 43 Pages
Year: 3

Curriculum

VC2M3N04

Add and subtract two- and three-digit numbers using place value to partition, rearrange and regroup numbers to assist in calculations without a calculator <ul> <li>using partitioning and part-part-whole models and the inverse relationship between addition and subtraction to solve addition or subtraction problems, making informal written ‘jottings’ to keep track of the numbers if necessary</li> <li>using physical or virtual grouped materials or diagrams to make proportional models of numbers to assist in calculations, for example, to calculate 214 + 325, representing 214 as 2 groups of 100, one group of 10 and 4 ones and 325 as 3 groups of 100, 2 groups of 10 and 5 ones, resulting in 5 groups of 100, 3 groups of 10 and 9 ones, which is 539</li> <li>choosing between standard and non-standard place value partitions to assist with calculations, for example, to solve 485 + 365, thinking of 365 as 350 + 15, then adding the parts, 485 + 15 = 500, 500 + 350 = 850</li> <li>solving subtraction problems efficiently by adding or subtracting a constant amount to both numbers to create an easier calculation; for example, 534 − 395, adding 5 to both numbers to make 539 − 400 = 139</li> <li>justifying choices about partitioning and regrouping numbers in terms of their usefulness for particular calculations when solving problems</li> <li>applying knowledge of place value to assist in calculations when solving problems involving larger numbers; for example, calculating the total crowd numbers for an agricultural show that lasts a week</li> </ul>
VC2M3A01

Recognise and explain the connection between addition and subtraction as inverse operations, apply to partition numbers and find unknown values in number sentences <ul> <li>partitioning numbers using materials, part-part-whole diagrams or bar models, and recording addition and subtraction facts for each representation, explaining how each fact is connected to the materials, diagrams or models (for example, 16 + 8 = 24, 24 − 8 = 16, 8 = 24 − 16)</li> <li>using the inverse relationship between addition and subtraction to find unknown values with a calculator or by counting on; for example, representing the problem ‘Peter had some money and then spent $375. Now he has $158 left. How much did Peter have to start with?’ as □ − $375 = $158 and solving the problem using $375 + $158 = $533; or solving 27 + □ = 63 using subtraction, □ = 63 – 27, or by counting on 27, 37, 47, 57, 60, 63, so add 3 tens and 6 ones, so □ = 36</li> <li>exploring Aboriginal and/or Torres Strait Islander Peoples’ stories and dances that show the connection between addition and subtraction, representing this as a number sentence and discussing how this conveys important information about balance in processes on Country/Place</li> </ul>
VC2M3A02

Extend and apply knowledge of addition and subtraction facts to 20 to develop efficient mental strategies for computation with larger numbers without a calculator <ul> <li>partitioning using materials and part-part-whole diagrams to develop subtraction facts related to addition facts, such as 8 + 7 = 15 therefore 15 − 7 = 8 and 15 − 8 = 7</li> <li>using partitioning to develop and record facts systematically (for example, ‘How many ways can 12 monkeys be spread among 2 trees?’, 12 = 12 + 0, 12 = 11 + 1, 12 = 10 + 2, 12 = 9 + 3, …), explaining how they know they have found all possible partitions</li> <li>understanding basic addition and related subtraction facts and using extensions to these facts; for example, 6 + 6 = 12, 16 + 6 = 22, 6 + 7 = 13, 16 + 7 = 23, and 60 + 60 = 120, 600 + 600 = 1200</li> </ul>

teaching resource

Addition Detectives PowerPoint

Updated: 22 Jun 2023

An engaging 43-slide PowerPoint styled as a detective story in which students are tasked with using different addition strategies to uncover suspects.

Editable: PowerPoint
Pages: 43 Pages
Year: 3

An engaging 43-slide PowerPoint styled as a detective story in which students are tasked with using different addition strategies to uncover suspects.

A bank has been broken into, and a vast sum of money has been stolen. It is up to your students to use their mental addition strategies to reveal the suspects and solve the crime.

This PowerPoint includes seven ‘investigations’, each focusing on a different addition strategy. The investigations include an example of the strategy, a question, an answer and a suspect that is revealed. The story concludes with a final set of questions that reveal the innocent suspects and identify the criminal.

Use this teaching presentation as a consolidation task across multiple lessons to build excitement in the classroom, or solve the crime in one session as a whole-class activity.

This presentation is best paired with the Addition Detectives Unit, which has lessons aligned to each investigation.

Addition strategies include:

concrete materials
bridging to ten
jump strategy
number boards
split strategy
linking addition and subtraction
compensation strategy.

To explore addition strategies in greater detail, take a look at the following teaching resources:

[resource:3600518][resource:3602914][resource:3602994][resource:3603058]

Take a look at the following segment from our Gamified Learning Using Interactive PowerPoints webinar. Resource Producer Tom will step through how to use this PowerPoint with your class.

Curriculum

VC2M3N04

Add and subtract two- and three-digit numbers using place value to partition, rearrange and regroup numbers to assist in calculations without a calculator <ul> <li>using partitioning and part-part-whole models and the inverse relationship between addition and subtraction to solve addition or subtraction problems, making informal written ‘jottings’ to keep track of the numbers if necessary</li> <li>using physical or virtual grouped materials or diagrams to make proportional models of numbers to assist in calculations, for example, to calculate 214 + 325, representing 214 as 2 groups of 100, one group of 10 and 4 ones and 325 as 3 groups of 100, 2 groups of 10 and 5 ones, resulting in 5 groups of 100, 3 groups of 10 and 9 ones, which is 539</li> <li>choosing between standard and non-standard place value partitions to assist with calculations, for example, to solve 485 + 365, thinking of 365 as 350 + 15, then adding the parts, 485 + 15 = 500, 500 + 350 = 850</li> <li>solving subtraction problems efficiently by adding or subtracting a constant amount to both numbers to create an easier calculation; for example, 534 − 395, adding 5 to both numbers to make 539 − 400 = 139</li> <li>justifying choices about partitioning and regrouping numbers in terms of their usefulness for particular calculations when solving problems</li> <li>applying knowledge of place value to assist in calculations when solving problems involving larger numbers; for example, calculating the total crowd numbers for an agricultural show that lasts a week</li> </ul>
VC2M3A01

Recognise and explain the connection between addition and subtraction as inverse operations, apply to partition numbers and find unknown values in number sentences <ul> <li>partitioning numbers using materials, part-part-whole diagrams or bar models, and recording addition and subtraction facts for each representation, explaining how each fact is connected to the materials, diagrams or models (for example, 16 + 8 = 24, 24 − 8 = 16, 8 = 24 − 16)</li> <li>using the inverse relationship between addition and subtraction to find unknown values with a calculator or by counting on; for example, representing the problem ‘Peter had some money and then spent $375. Now he has $158 left. How much did Peter have to start with?’ as □ − $375 = $158 and solving the problem using $375 + $158 = $533; or solving 27 + □ = 63 using subtraction, □ = 63 – 27, or by counting on 27, 37, 47, 57, 60, 63, so add 3 tens and 6 ones, so □ = 36</li> <li>exploring Aboriginal and/or Torres Strait Islander Peoples’ stories and dances that show the connection between addition and subtraction, representing this as a number sentence and discussing how this conveys important information about balance in processes on Country/Place</li> </ul>
VC2M3A02

Extend and apply knowledge of addition and subtraction facts to 20 to develop efficient mental strategies for computation with larger numbers without a calculator <ul> <li>partitioning using materials and part-part-whole diagrams to develop subtraction facts related to addition facts, such as 8 + 7 = 15 therefore 15 − 7 = 8 and 15 − 8 = 7</li> <li>using partitioning to develop and record facts systematically (for example, ‘How many ways can 12 monkeys be spread among 2 trees?’, 12 = 12 + 0, 12 = 11 + 1, 12 = 10 + 2, 12 = 9 + 3, …), explaining how they know they have found all possible partitions</li> <li>understanding basic addition and related subtraction facts and using extensions to these facts; for example, 6 + 6 = 12, 16 + 6 = 22, 6 + 7 = 13, 16 + 7 = 23, and 60 + 60 = 120, 600 + 600 = 1200</li> </ul>

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8 Comments

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Julie Cadden · 3 years ago

This is awesome! Kids love it! Is there a Subtraction Detectives?
- Janeen · 3 years ago
  
  Hi Julie Thank you so much for your lovely comment! We're so glad your students are enjoying the resource. At this stage we don't have a Subtraction Detectives resource. Please feel free to make this suggestion at our 'Suggest a Resource' page. https://www.teachstarter.com/au/suggest-a-resource/
Sónia Veiga · 3 years ago

Link "Addition detectives unit" does not go to unit at all but generic resources page https://www.teachstarter.com/?go=3557286
- Paul (Teach Starter) · 3 years ago
  
  Hi Sonia, Thanks for letting us know. We'll get right onto that! In the meantime, you can access the unit at https://www.teachstarter.com/au/unit-plan/addition-detectives/