Summary
Fixit with Karen
Understanding the written method for multiplication can be tricky for many children, especially those who have dyscalculia or other specific maths difficulties.
Before attempting to use the method, it is important to ensure the following prerequisite skills are in place:
- A good understanding of multiplication, knowing that it is the same as repeatedly adding a number
- The ability to partition a number into tens and ones.
- Some confidence and fluency with recall of multiplication facts.
- Understanding of place value and applying this to times table facts – e.g. using 3×4=12 to know that 30×4=120.
- The ability to mentally add a single digit to a 2-digit number and to use the written column method for addition.
Whilst learning to use the written method, a multiplication square can provide valuable support by removing any anxiety about recalling times table facts, allowing the focus to instead be on understanding the process.
Using Cuisenaire rods, a calculation such as 14×3 can be shown by making 14 (with a 10 rod and a 4 rod) three times. It can then be seen how the calculation is split into two parts – there are 3 ten rods (so 3×10=30) and 3 four rods (3×4=12). These two separate answers can then be added together (30+12=42) to get the final answer to the calculation.
Place value tens and ones blocks can be used instead of Cuisenaire rods, or online resources provide another alternative: https://mathsbot.com/manipulatives/rods
Moving away from using manipulatives, the Cuisenaire rods can instead be drawn as rectangular blocks. So in the previous example, this would be a rectangle that is 10 long and 3 wide to represent the 3 ten rods, and a second rectangle which is 4 long and 3 wide to represent to 3 four rods. The 2 calculations can then be carried out and added together in the same way.
The final step, using just the abstract written method, involves seeing the multiplication as a shorthand way of recording a repeated addition. We first multiply the ones by 3, so 3×4=12 (which is the same as 4+4+4=12). Then we multiply the tens by 3, so 10×3=30 (the same as 10+10+10). The recording process is actually the same as for the written column addition method.
More great blogs from Karen can be found on our website here – https://dyscalculianetwork.com/insights-events/
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https://www.fixitmaths.com/
