Focus on Learning
Year 1/2: Mrs Amanda Bartholomew
Focus: Mathematics
In Year 1/2, we are currently working on developing a range of strategies to solve subtraction problems efficiently. One of the main focuses in our classroom is for students to gain confidence in explaining their problem solving strategies and for them to communicate their mathematical thinking clearly.
Counting-Back
One of the first strategies we learn to help us to subtract is counting back. Here we can use "concrete materials" (counters, drawings, fingers, blocks, number charts) as markers to count back from a larger number.
In the pictures below, students are using interlocking cubes and drawings to count back from the larger number to solve the subtraction problem.
Using an Empty Number Line
This strategy builds on counting back using "concrete materials", here the students draw an empty number line and use it to help them "jump back" or count down from the larger number. First you start by subtracting 1-digit numbers and then move on to counting back using 2-digit numbers.
In the pictures below, students are using our mini whiteboards and empty number lines to solve a range of subtraction problems using 1 and 2-digit numbers.
The Jump Strategy
As the students become more efficient at solving subtraction problems they use fewer jumps on the number line.
Other Effective Strategies
Here Hayden has used Bridging to 10 to help him solve his subtraction problem. His subtraction problem was 13 - 4 =...He bridged 13 down to 10 by taking 3 away...13 - 3 = 10, then all he needed to do was to take away 1 more to get to 9. A very clever strategy to use!