Addition and Subtraction 25 EVEN: 2 4 6 8 0 ODD: 1 3 5 7 9 Addition and Subtraction 25 Patterns and Algebra 21

Addition and Subtraction 25 6 + 8 = 14 Addition and Subtraction 25 Patterns and Algebra 21

Addition and Subtraction 25 8 – 6 = 2 Addition and Subtraction 25 Patterns and Algebra 21

Addition and Subtraction 25 7 + 5 = 12 Addition and Subtraction 25 Patterns and Algebra 21

Addition and Subtraction 25 7 – 5 = 2 Addition and Subtraction 25 Patterns and Algebra 21

Addition and Subtraction 25 7 + 2 = 9 Addition and Subtraction 25 Patterns and Algebra 21

Addition and Subtraction 25 7 - 2 = 5 Addition and Subtraction 25 Patterns and Algebra 21

Addition and Subtraction 25 Check calculations 12 984 + 37 846 = odd? even? 365 + 287 = odd? even? 16 + 37 = odd? even? 86 + 8 = odd? even? Addition and Subtraction 25 Patterns and Algebra 21

Addition and Subtraction 25 2 odd numbers, the sum will be even. 2 odd numbers, the difference will be even. 2 even numbers, the sum will be even. 2 even numbers, the difference will be even. 1 odd and 1 even number, the sum will be odd. 1 odd and 1 even number, the difference will be odd. 3 odd numbers, the sum will be odd. 3 even numbers, the sum will be even. 1 odd and 2 even number, the sum will be odd. 2 odd and 1 even number, the sum will be even. Addition and Subtraction 25 Patterns and Algebra 21

Addition and Subtraction 25 Investigation: Select cards to make combinations of odd and even numbers to add and subtract. *2 even numbers *2 odd numbers *3 even numbers *3 odd numbers *1 odd and 1 even *2 odd and 1 even *2 even and 1 odd Explain which combination result in odd numbers and which combinations result in even numbers. Reflection: What happens when we add and subtract combinations of odd and even numbers? Problem Solving Lola said that 12 365 + 85 268 equals 97 633. Could she be right? Problem Solving Billy said that 18 654 – 13 827 equals 4828. Could he be right? Problem Solving Helen said she partitioned 835 into 3 odd numbers. Could she be right? Addition and Subtraction 25 Patterns and Algebra 21

Addition and Subtraction 25 Patterns and Algebra 21

Addition and Subtraction 25 Investigation: Make number patterns that repeat by adding or subtracting even numbers or adding odd numbers. Record them, identifying relationships. For example, Start with an even number and repeatedly add or subtract an even number. Start with an odd number and repeatedly add or subtract an odd number. Start with an even number and repeatedly add or subtract an odd number. Start with an odd number and repeatedly add or subtract an even number. Repeatedly alternate between adding or subtracting an odd and an even number. Reflection: What happens when we add and subtract combinations of odd and even numbers? Addition and Subtraction 25 Patterns and Algebra 21

Addition and Subtraction 25 Investigation: Investigate partitioning numbers into 2 parts. Check your calculations using the relationships when adding odd and even numbers. For example, When you partition an even number into 2 parts, are both partitions odd, even or a combination of odd and even? When you partition an odd number into 2 parts, are both partitions odd, even or a combination of odd and even? Reflection: What happens when we add and subtract combinations of odd and even numbers? Addition and Subtraction 25 Patterns and Algebra 21

Addition and Subtraction 25 Investigation: Investigate partitioning numbers into 3 parts. Check your calculations using the relationships when adding odd and even numbers. For example, When you partition an even number into 3 parts, are all partitions odd, even or a combination of odd and even? When you partition an odd number into 3 parts, are all partitions odd, even or a combination of odd and even? Reflection: What happens when we add and subtract combinations of odd and even numbers? Addition and Subtraction 25 Patterns and Algebra 21