AC9M2N04
Year 2
Mathematics
AC9M2N04 | Year 2 Mathematics: Number
Content Descriptor
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
Strand
Number
Substrand
Number
This content descriptor sets out learning for Year 2 Mathematics. Use it to plan lessons and assessment with the Australian Curriculum v9.
Elaborations
- • Elaboration 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
- • Elaboration 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
- • Elaboration 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
- • Elaboration 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
- • Elaboration 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?”
- • Elaboration using First Nations Australians’ stories and dances to understand the balance and connection between addition and subtraction, representing relationships as number sentences
Plan a lesson from this content description.
Start freeAchievement standard statements this supports
- 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.See it on the standard page →
- They use mathematical modelling to solve practical additive and multiplicative problems, including money transactions, representing the situation and choosing calculation strategies.See it on the standard page →
- Students recall and demonstrate proficiency with addition and subtraction facts within 20 and multiplication facts for twos.See it on the standard page →