3 Maths Mistakes: Alerting Parents
Learn them now; avoid needing to unlearn them later.
Think back to your primary school days, sitting in your maths lessons. Can you remember particular catch phrases that were drilled into you as a child? Chances are, some of these catch phrases may ring a bell! Learn more about how the way children are taught maths has changed.
At the time, yes, they may pose to be useful for teachers and parents to use when helping children. However, as you’ll soon discover, these catch phrases which are intended to help your child, can in fact lead to misconceptions, causing unnecessary confusion later in life.
Multiplying by 10: "Just add a zero"
When teaching how to multiply by a power of 10, an all too common misconception is adding zeros on the end.
This may be a pattern for some values, however this misconception becomes very damaging when suddenly this rule doesn’t work correctly.
Instead; let’s try this:
How to multiply by 10
When multiplying by 10, we make it 10 times the size.
Look at the shift in place value and see how zero is used as a “place holder”.
How to multiply by 100
When multiplying by 100, we make it 100 times the size.
Look at the shift in place value and see how zero is used as a “place holder”.
Column method subtraction: "3 subtract 5 we cannot do...”
Here’s another “rule” you might hear echoing from your schooling years. This is a common catch phrase often used when teaching the formal method of column subtraction, when a digit of the number to be subtracted is larger than its corresponding digit in the number it is subtracted from.
Stating that you cannot subtract a larger number from a smaller number is a false mathematical statement.
Instead; let’s try this:
These suggestions very much depend on your child’s current level of understanding and the context:
Change your statement to say that it will equal “less than zero”
Draw a number line to show that numbers less than zero exist
Look at the place value of digits and how they can be partitioned to help with subtraction
The bottom line is, although learning how to subtract larger numbers from smaller numbers is a more advanced skill, it should not be confused by misconceptions.
Division: “The biggest number has to go first”
Here is an example of a very common error children make when learning division:
It is also common for this type of error to be corrected with a reminder about how when we divide, the larger number needs to go first. This is another false mathematical concept, so try and avoid saying it in this way.
Instead; let’s try this:
Draw a picture
Draw a picture or use blocks to represent the division problem visually, helping them to ‘see’ their error.
Bar Model
A bar model is another useful way to visually represent the problem.
“Shared Equally Between”
As you read the number sentence focus on the parts of an equal sharing problem. This language is also useful when referring to the bar model.
Real world examples
Use examples that they can understand at their current level to help grasp the concept of dividing.
E.g. 2 kg of dog food that has to be shared equally between 4 dogs in the pet shop
Conclusion
Sometimes giving a simple rule can work in the moment, but it’s important to consider the confusion it may cause in the long run. Next time your child comes to you asking for help with their maths homework, have a go at using one of these strategies!