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Published byCecil Spencer Modified over 8 years ago
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1 Addition
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57 Models for addition Combining two sets of objects (aggregation) 2
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57 Models for addition Combining two sets of objects (aggregation) 3
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57 Models for addition Combining two sets of objects (aggregation) 4
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57 Models for addition Combining two sets of objects (aggregation) 5
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57 Models for addition Adding on to a set (augmentation) Counting on with a bead bar/number line Combining two sets of objects (aggregation) 12 Issue: Tend to count one set, count the other and then count all. 5 6 7 8 9101112 Issue: Requires fluency with counting from any number. 12 5 0 + 7 Issues: Bead bar is a useful bridge from cardinal to ordinal. Number line helps to stop counting all Also: Bead bar and number line (showing 10s) encourages use of number bonds and place value for added efficiency. 10 +2+5 6
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More than single digits? 7
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10 TensOnes 74 + 1111 11 1 1 1 1 11 52 10
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TensOnes 74 + 1111 11 1 1 1 1 11 52 10
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TensOnes 74 + 1111 11 1 1 1 1 11 52 10
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TensOnes 74 + 1111 11 1 1 1 1 11 52 10
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TensOnes 74 + 111111111111 52 10 12
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10 TensOnes 74 + 111111111111 52 10 2 1
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TensOnes 74 + 111111111111 52 10 2 1
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TensOnes 74 + 111111111111 52 10 2 1
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TensOnes 74 + 111111111111 52 10 2 1
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TensOnes 74 + 111111111111 52 10 2 1 7
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25 Subtraction
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12 Models for subtraction Removing items from a set (reduction or take-away) - 1- 2- 3- 4- 5= 7 Issue: Relies on ‘counting all’, again. Comparing two sets (comparison or difference) Issue: Useful when two numbers are ‘close together’, where ‘take-away’ image can be cumbersome Seeing one set as partitioned Seeing 12 as made up of 5 and 7 Issue: Helps to see the related calculations; 5+7=12, 7+5=12, 12-7 = 5 and 12-5=7 as all in the same diagram N.B. When this is done on a bead bar, there are links with both counting back and difference on a number line 26
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Models for subtraction Counting back on a number line Finding the difference on a number line 12 0 - 5 7 Issue: Number line helps to stop ‘counting all’. Also: Knowledge of place value and number bonds can support more efficient calculating 12 0 5 7 Issue: Useful when two numbers are ‘close together’, use of number bonds and place value can help. 52 10 -2-3 27
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72 - 47 More than single digits? 28
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72 - 47 29
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72 - 47 This is now “Sixty- twelve” 7 1 2 6 30
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72 - 47 31
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72 - 47 32
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72 - 47= 25 33
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10 1 TensOnes 1 72 74 - 10 1 6 1 1 1 1 1 11 1 1 1
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TensOnes 72 74 - 1111 11 1 1 1 1 11 1 6
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10 TensOnes 72 74 - 1111 11 1 1 1 1 11 1 6
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10 TensOnes 72 74 - 1111 11 1 1 1 1 11 1 6
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10 TensOnes 72 74 - 1111 11 1 1 1 1 11 1 6
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10 TensOnes 72 74 - 1111 11 1 1 1 1 11 1 6 5
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10 TensOnes 72 74 - 1111 11 1 1 1 1 11 1 6 5
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10 TensOnes 72 74 - 1111 11 1 1 1 1 11 1 6 5 10
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TensOnes 72 74 - 1111 11 1 1 1 1 11 1 6 5 10
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TensOnes 72 74 - 1111 11 1 1 1 1 11 1 6 52 10
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Addition and Subtraction: Both Ways
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10 1 TensOnes 1 72 74 - 10 1 6 1 1 1 1 1 11 1 1 1
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TensOnes 72 74 - 1111 11 1 1 1 1 11 1 6
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10 TensOnes 72 74 - 1111 11 1 1 1 1 11 1 6
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10 TensOnes 72 74 - 1111 11 1 1 1 1 11 1 6
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10 TensOnes 72 74 - 1111 11 1 1 1 1 11 1 6
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10 TensOnes 72 74 - 1111 11 1 1 1 1 11 1 6 5
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10 TensOnes 72 74 - 1111 11 1 1 1 1 11 1 6 5
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10 TensOnes 72 74 - 1111 11 1 1 1 1 11 1 6 5 10
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TensOnes 72 74 - 1111 11 1 1 1 1 11 1 6 5 10
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TensOnes 72 74 - 1111 11 1 1 1 1 11 1 6 52 10
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TensOnes 74 + 1111 11 1 1 1 1 11 52 10
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TensOnes 74 + 1111 11 1 1 1 1 11 52 10
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TensOnes 74 + 1111 11 1 1 1 1 11 52 10
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TensOnes 74 + 1111 11 1 1 1 1 11 52 10
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TensOnes 74 + 111111111111 52 10 12
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10 TensOnes 74 + 111111111111 52 10 2 1
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TensOnes 74 + 111111111111 52 10 2 1
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TensOnes 74 + 111111111111 52 10 2 1
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TensOnes 74 + 111111111111 52 10 2 1
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TensOnes 74 + 111111111111 52 10 2 1 7
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