# Primary

### Foundations of Subtraction

##### Chapter 1: Revisiting the foundations
 LO 1: Differentiating between numbers, numerals and digits LO 2: Recognising the importance of unit (‘1’) LO 3: Analysing multiple units LO 4: Explaining importance of ‘like unit’ LO 5: Counting and comparing ‘unlike units’? LO 6: Discussing the use of decimal number system LO 7: Exploring ‘value of place’ in everyday living LO 8: Identifying place value and face value of digits LO 9: Visualising numbers in decimal number system LO 10 Interpreting numbers as mixture of place value packets LO 11: Experiencing set in the decimal number system

##### Chapter 2: Context of subtraction
 LO 1: Recalling arithmetic operations LO 2: Lessons from addition LO 3: Lessons from multiplication LO 4: Discovering the existential need for subtraction operation LO 5: Listing examples of difference in daily life LO 6: Comparing things for difference LO 7: Knowing how to learn subtraction LO 8: Preparing children to learn subtraction LO 9: Elaborating subtraction as more varied, and complex operation

##### Chapter 3: Introduction to subtraction
 LO 1: Discovering the common threads across ‘subtraction situations’ LO 2: Exploring ‘Takeaway’ situations LO 3: Appreciating separation situations LO 4: Understand comparison situations LO 5: Knowing why 'what is left' is an important number? LO 6: Satisfying if difference is the right term for all subtraction situations LO 7: Expressing subtraction as a simple, universally acceptable narrative LO 8: Being comfortable with ‘–’

##### Chapter 4: Macro subtraction process
 LO 1: Visualising subtraction expressions LO 2: Subtracting in pairs LO 3: Subtracting like units LO 4: Subtracting unlike units LO 5: Detailing subtraction of unlike units LO 6: Reasoning subtraction of unlike units LO 7: Revisiting backward counting LO 8: Visualising subtraction as backward skip counting

##### Chapter 5: Micro subtraction process
 LO 1: Implementing simple subtraction expressions LO 2: Exploring minuend LO 3: Exploring subtrahend LO 4: Exploring difference LO 5: Investigating the difference between 8 – 1 – 1 and 8 – 2 LO 6: Reading 22 – 2 – 3 – 4 – 5 – 6 LO 7: Analysing 30 – 12 – 8 + 10 – 10 + 5 LO 8: Exploring 8 – 3, as comparison of 8 and 3 LO 9: Exploring 8 – 3, as ‘takeaway’ of 3 out of 8 LO 10: Exploring 8 – 3, as ‘separation’ 3 out of 8 LO 11: Appreciating 7 – 0, 0 – 7 LO 12: Detailing 7 - 7 LO 13: Exploring how 7 - 3 is different from 3 - 7 LO 14: Relating multiplication and repeated subtraction

##### Chapter 6: Macro subtraction operation
 LO 1: Experiencing subtraction operation LO 2: Knowing what borrow represents in subtraction LO 3: Explaining why borrow is always ‘1’ LO 4: Appreciating that borrow can’t be the exact quantity needed LO 5: Exploring the possible values of borrow LO 6: Applying subtraction operation

##### Chapter 7: Micro subtraction operation
 LO 1: Investigating subtraction of numerals from the right LO 2: Subtracting multiple subtrahends LO 3: Explaining cascade borrow LO 4: Subtracting a bigger number from a smaller number