Planning tool

Students:

• model and describe addition and subtraction in different ways using part-part-whole knowledge
• solve and model story problems involving addition and subtraction of numbers to 20
• choose reliable strategies to solve addition and subtraction, for example, they use counting-up and counting-down along with known number facts to support computation
• recognise and use the + and − symbols and the equals sign (=) to represent addition and subtraction.

Some students may:

• think of the equals sign (=) as ‘here comes the answer’ instead of seeing it as a balance between equivalent statements. To address this, regularly present addition and subtraction problems in different ways. For example: 7 − 5 = ▢ can also be written as ▢ = 7 − 5 and 2 = 7 − ▢.
• not understand the commutative property in addition; that the order of the addends can be changed and it will not affect the answer and so draw on this when solving additive problems. To address this, use physical materials to model the property and provide opportunities to explore, test and think about whether this property always works.
• not understand the associative property in addition; that it doesn’t matter which order you add numbers when adding three numbers or more. To address this, explicitly teach this idea and how useful it is to make solving problems easier. In 3 + 6 + 7, for instance, adding the 3 and 7 to make 10, and then adding 6 to make 16 can be considered an easier path. Include a focus on these kinds of addition problems during regular classroom talks to support fluency with this idea.
• think that adding zero (e.g. 5 + 0) will result in a larger number because they have learned that ‘adding makes numbers larger’. Similarly, when subtracting zero (e.g. 5 − 0) they think the answer will be smaller than the minuend. To address this, provide repeated opportunities to explore problems that add and subtract zero.

The Learning from home activities are designed to be used flexibly by teachers, parents and carers, as well as the students themselves. They can be used in a number of ways including to consolidate and extend learning done at school or for home schooling.

Learning intention

• We are learning to solve addition and subtraction problems.

Why are we learning about this?

• We use addition and subtraction in everyday life.

What to do:

When engaged in creative play, notice situations involving addition and subtraction. Model curiosity and pose questions such as:

• You’ve some green blocks there and some red blocks. How many of each? How many blocks altogether?
• There are 4 wheels on the truck and another 4 wheels on the car. How many wheels altogether? How do you know for sure?
• How many gumnuts have you there? What if I took these two, how many would be left?

Read storybooks and discuss situations involving addition and subtraction. Model curiosity and pose questions such as:

• There are 5 lemons here … and 2 more lemons here. How many altogether?
• Dog is joined by his friends. How many animals are there now?
• Oh, the goat just ate another apple! There were 5 apples. How many are left now?

Link addition and subtraction to everyday situations. For example:

• Provide opportunities to play with, sort and add up money.
• When shopping, or when playing shops, talk about the total number of items in the basket. For example: There are 4 apples, 5 bananas and 2 oranges. How many pieces of fruit altogether?
• When drawing pictures, notice and describe additive aspects such as the number of legs on two dogs (4 and 4) and the number of legs on the person (2) makes a total of 10 legs.
• When making money calculations use whole dollars. For example: The milk costs $3 and the bread costs $3. So altogether, how much do we need to pay? If we pay with a $10 note, how much change will we get?

Play games involving additive thinking. For example:

• Play Concentration (also known as Memory) where two sets of cards are numbered 0 to 10. In this variation, the aim is to collect the most pairs of cards as possible that make 10.

Think about and discuss different ways of solving addition and subtraction. For example, To solve 7 + 6 you might decide to:

• Count up from 7, 6 times (...8, 9, 10, 11, 12, 13)
• Break the 6 up into 3 and 3 to ‘make a friendly 10’: 7 + 3 = 10; 10 + 3 = 13
• Start with a known doubles fact of 6 + 6 = 12. Then add 1 more to get 13.

Know that mistakes are a normal part of building mathematical understanding. Be curious about mistakes and see them as opportunities to learn. Take plenty of time to solve problems.

Success criteria

I can:

• use language like ‘____ and _____ makes _____’ and ‘____ plus ____ equals’ to describe addition
• use language like ‘_____ take away ______ leaves’ and ‘____ minus ____ equals’ to describe subtraction
• use strategies such as ‘counting up’, ‘breaking numbers apart’ and ‘using known facts’ to help solve addition and subtraction problems.