MAE3270 Module 2 - Lecture 2: Number sense and fluency

Chapter 1: Introduction

  • Multiplicative thinking involves working with a greater range of numbers

    • Numbers of increasing magnitude: whole numbers, decimals, fractions, and percentages

  • Multiplicative thinking involves recognizing and solving problems involving multiplication or division

    • Communication can be done through discussion, words, diagrams, symbols, expressions, and algorithms

  • Understanding the concept of multiplication

    • Encouraging students to understand that 3 multiplied by 4 means 3 lots of 4 or 4 lots of 3

    • Encouraging students to recognize and identify this notion through various representations

    • Examples of representations: tray of muffins, bags of apples, combinations of t-shirts and shorts, length of rope, bags of carrots, DVDs

    • Putting multiplication in a real-life context and perspective

  • Developing an understanding of multiplicative thinking

    • Helps understand the structure of the base ten number system

    • Understanding the place value when moving to the right or left of the decimal point

    • Helps with adding and subtracting fractions by understanding factors and multiples

  • Representations for 3 multiplied by 4

    • Utilizing counters

    • Using arrays

  • Multiplication and division

    • Multiplication is repeated addition

    • Arrays and combinations can help represent multiplication

    • Division is the inverse of multiplication

    • Equal sharing or equal grouping

  • Models for multiplication

    • Counters

    • Arrays

    • Number line

Chapter 2: Tackling Tables

  • Array for multiplication to demonstrate repeated addition

  • Properties of multiplication:

    • Multiplicative property of 0: any number multiplied by 0 is 0

    • Multiplicative property of 1: any number multiplied by 1 remains the same

    • Commutative property of multiplication: order of multiplication does not affect the product

    • Associative property of multiplication: factors can be grouped in any way without affecting the product

    • Distributive property of multiplication: operation can be distributed across an equation

  • Language to help students understand multiplication:

    • How many groups of

    • How many lots of

    • How many or how much altogether

    • Per or each

    • Product

    • Arrays and combinations

  • Hawkswan's Tackling Tables:

    • Strategies, activities, and games to help students understand times tables

  • Importance of multiplicative thinking before rote learning times tables

  • Activities and strategies help students learn times tables without rote memorization

Chapter 3: Blank Times Tables

  • If students struggle with certain multiplication tables, a trick can be used

    • A times table chart is shown, going up to the 9 times tables

    • Students quickly grasp the tens and elevens times tables

    • Knowledge of the tens and twos times tables, along with the distributive property, allows students to combine them to get the twelves times tables

    • Students can be provided with a blank times tables chart to color in certain aspects

    • Students can black out the times tables that multiply by 0, as the answer will be 0

    • The column and row for the one times tables can be blanked out, as any number multiplied by 1 is itself

    • The orange numbers on an angle represent the square numbers, which students learn early on

    • The green and white sections on either side of the square numbers are mirror images

    • Due to the commutative property, only the green or white section needs to be memorized

    • Within the green section, the two and five times tables are easy to learn

    • Overall, students don't need to memorize as many multiplication tables if they understand the patterns and properties

Chapter 4: Factors And Multiples

  • A multiplication grid, like the times tables chart, helps with understanding factors and multiples

  • Factors are smaller numbers that divide evenly into another number

    • The factors of 6 are 1, 2, 3, and 6

    • Factors can be paired up to multiply and give the original number

  • Multiples are numbers that result from counting in multiples of a certain number

    • Multiples of 6 include 6, 12, 18, 24, 30, etc.

  • The multiplication grid shows the factors of a number, such as 48

    • The factors of 48 are 6 and 8

    • Other rows and columns in the grid also show factors of 48

    • Further factors of 48 include 24 and 2, as well as 1 and 48

  • An array can be used to demonstrate factors and multiples

    • The number of rows and columns in the array represents the factors

    • The product of the two numbers is the multiple

Chapter 5: Financial Literacy and Number Fluency

  • Consumer and financial literacy is important for students and young Australians in the 21st century

    • Students need to understand how to work with money and become confident in financial matters

    • Understanding percentages is crucial for comprehending income tax, interest rates, and financial transactions

  • Fluency in addition and subtraction is necessary for representing money values and calculating change

  • Fluency in multiplication and division is needed for calculating purchases and solving related problems

  • Students should be able to calculate percentage discounts and increases accurately

  • Planning and amending a budget is important, distinguishing between essential and optional expenditures

  • Estimation and rounding are valuable skills for checking the reasonableness of results

    • Estimation helps students recognize whether an answer makes sense in the context of a question

    • Estimation saves time by providing a rough answer without going through the whole calculation process

Final Word on Number Sense and Understanding

  • Good number sense is essential for efficient computation

  • Efficient mental techniques should be encouraged

  • Unthinking recall of algorithms or procedures is not ideal for complex calculations

  • Understanding the properties and language of mathematical operations is important

  • Learning about money and financial maths in a relevant and relatable context is crucial

  • Estimation is a powerful tool for recognizing the reasonableness of results