AC9M2N04 Year 2 Mathematics

AC9M2N04 – Year 2 Mathematics: null

Strand

Number

Substrand

Number

This Content Descriptor from Year 2 Mathematics provides the specific knowledge and skills students should learn. Use it to plan lessons, create learning sequences, and design assessments that align with the Australian Curriculum v9.

Content Descriptor

add and subtract one- and two-digit numbers, representing problems using number sentences, and solve using part-part-whole reasoning and a variety of calculation strategies

Elaborations

• using the associative property of addition to assist with mental calculation by partitioning, rearranging and regrouping numbers using number knowledge, near doubles and bridging to $10$ strategies; for example, calculating $7 + 8$ using $7 + (7 + 1) = (7 + 7) + 1$ , the associative property and near doubles; calculating $7 + 8$ using the associative property and bridging to $10$ , $7 + (3 + 5) = (7 + 3) + 5$
• using strategies such as doubles, near doubles, part-part-whole knowledge to $10$, bridging tens and partitioning to mentally solve problems involving two-digit numbers; for example, calculating $56 + 37$ by thinking $5$ tens and $3$ tens is $8$ tens, $6 + 7 = 6 + 4 + 3$ is one $10$ and $3$, and so the result is $9$ tens and $3, 93$
• representing addition and subtraction problems using a bar model and writing a number sentence, explaining how each number in the sentence is connected to the situation
• using mental strategies and informal written jottings to help keep track of the numbers when solving addition and subtraction problems involving two-digit numbers and recognising that zero added to a number leaves the number unchanged; for example, in calculating $34 + 20 = 54, 3$ tens add $2$ tens is $5$ tens which is $50$, and $4$ ones add zero ones is $4$ ones which is $4$, so the result is $50 + 4 = 54$
• using a physical or mental number line or hundreds chart to solve addition or subtraction problems, by moving along or up and down in tens and ones; for example, “I was given a $\$100$ gift card for my birthday and spent $\$38$ on a pair of shoes and $\$15$ on a t-shirt. How much money do I have left on the card?”
• using First Nations Australians’ stories and dances to understand the balance and connection between addition and subtraction, representing relationships as number sentences

Achievement Standard This Supports

This Content Descriptor contributes to the following Achievement Standard:

Year 2 ASMATY2

Year 2 Mathematics Achievement Standard

By the end of Year 2, students order and represent numbers to at least 1000, apply knowledge of place value to partition, rearrange and rename two- and three-digit numbers in terms of their parts, and regroup partitioned numbers to assist in calculations. They use mathematical modelling to solve practical additive and multiplicative problems, including money transactions, representing the situation and choosing calculation strategies. Students identify and represent part-whole relationships of halves, quarters and eighths in measurement contexts. They describe and continue patterns that increase and decrease additively by a constant amount and identify missing elements in the pattern. Students recall and demonstrate proficiency with addition and subtraction facts within 20 and multiplication facts for twos. They use uniform informal units to measure and compare shapes and objects. Students determine the number of days between events using a calendar and read time on an analog clock to the hour, half hour and quarter hour. They compare and classify shapes, describing features using formal spatial terms. Students locate and identify positions of features in two-dimensional representations and move position by following directions and pathways. They use a range of methods to collect, record, represent and interpret categorical data in response to questions.