Math K-6 WS - K-6 Educational Resources

MathematicsK-6 Stage1
4.1 Addition and Subtraction
Strand – Number Syllabus Content p 47
NS1.2
Uses a range of mental strategies and informal recording
methods for addition and subtraction involving one- and twodigit
numbers
WM
Questioning
Asks questions that
could be explored using
mathematics in relation
to Stage 1 content
Students learn about
Sample Units of Work
Working Mathematically Outcomes
Applying Strategies
Uses objects, diagrams,
imagery and
technology to explore
mathematical problems
❚ representing subtraction as the difference between two
numbers
❚ using the terms ‘add’, ‘plus’, ‘equals’, ‘is equal to’, ‘take
away’, ‘minus’ and ‘the difference between’
❚ recognising and using the symbols +, – and =
❚ recording number sentences using drawings, numerals,
symbols and words
❚ using a range of mental strategies and recording strategies
for addition and subtraction, including
– counting on from the larger number to find the total of
two numbers
– counting back from a number to find the number remaining
– counting on or back to find the difference between
two numbers
– using doubles and near doubles
eg 5 + 7: double 5 and add 2 more
– combining numbers that add to 10
eg 4 + 7 + 8 + 6 + 3 + 1: group 4 and 6, 7 and 3 first
– bridging to ten
eg 17 + 5: 17 and 3 is 20 and add 2 more
❚ using related addition and subtraction number facts to at
least 20 eg 15 + 3 = 18, so 18 – 15 = 3
❚ using concrete materials to model addition and subtraction
problems involving one- and two-digit numbers
❚ using bundling of objects to model addition and
subtraction with trading
❚ using a range of strategies for addition and subtraction of
two-digit numbers, including
– split strategy
– jump strategy (as recorded on an empty number line)
❚ performing simple calculations with money including
finding change and rounding to the nearest 5c
Communicating
Key Ideas
Describes mathematical
situations and methods
using everyday and
some mathematical
language, actions,
materials, diagrams and
symbols
Model addition and subtraction using concrete materials
Develop a range of mental strategies and informal recording
methods for addition and subtraction
Record number sentences using drawings, numerals, symbols
and words
Reasoning
Students learn to
Supports conclusions
by explaining or
demonstrating how
answers were obtained
Knowledge and Skills Working Mathematically
42
❚ recall addition and subtraction facts for numbers to at
least 20 (Applying Strategies)
❚ use simple computer graphics to represent numbers and
their combinations to at least 20 (Applying Strategies)
❚ pose problems that can be solved using addition and
subtraction, including those involving money (Questioning)
❚ select and use a variety of strategies to solve addition and
subtraction problems (Applying Strategies)
❚ check solutions using a different strategy
(Applying Strategies, Reasoning)
❚ recognise which strategy worked and which did not work
(Reasoning, Reflecting)
❚ explain why addition and subtraction are inverse
(opposite) operations (Communicating, Reasoning)
❚ explain or demonstrate how an answer was obtained for
addition and subtraction problems
eg showing how the answer to 15+8 was obtained using
a jump strategy on an empty number line
+5 +3
______________________________
15 20 23
(Communicating, Reasoning)
Reflecting
❚ use a variety of own recording strategies
(Applying Strategies, Communicating)
Links mathematical
ideas and makes
connections with, and
generalisations about,
existing knowledge
and understanding in
relation to Stage 1
content
❚ recognise equivalent amounts of money using different
denominations eg 50c can be made up of two 20c coins
and a 10c coin (Reflecting, Applying Strategies)
❚ calculate mentally to give change (Applying Strategies)