# Tag Info

Accepted

### Which product of single digits do children usually get wrong?

https://www.theguardian.com/news/datablog/2013/may/31/times-tables-hardest-easiest-children There are links to a dataset in the article. As far as I can tell, this isn't a formal study: But some new ...
• 5,733

### Is this primarily a "rote computational trick" for multiplication by 9?

Anything that is just a trick leads to students having wrong ideas about what math is. But methods that help students see the patterns can help them learn the multiplication facts, along with getting ...
• 20.8k

### Is this primarily a "rote computational trick" for multiplication by 9?

Yes. This is also a trick that you can do on your fingers, too. For instance, let's say you wanted to calculate $9\times3$. Hold out your hands and bend your third finger down as shown. So nine ...
• 5,619

### What are the arguments for and against learning the multiplication table by heart?

Let me add my 2 cents in. As someone who grew up in Latin America (where the tables were drilled into us, or else) and who now tutors mathematics, more than once I've had the experience of students ...
• 543
Accepted

### How do I explain the distributivity of multiplication to a student without using the analogy of areas?

It depends on how the student conceptualises multiplication. First, find that out. Then design an approach that uses it. For example, if they think of multiplication as repeated addition, then you ...

### How do I explain the distributivity of multiplication to a student without using the analogy of areas?

This is based on a framing device I used in a Khan Academy comment helping students get an intuitive appreciation of the distributive rule. It is just a description of $a(b+c)=ab+ac$, but it might be ...
• 5,619

### Is this primarily a "rote computational trick" for multiplication by 9?

To add on to the other answers, the reason this works is because we use the decimal system, a.k.a. the base-10 system, for our everyday maths. The multiples of the number that is one less than the ...
• 271

### Arguments against multiplication by 'stacking'

Some context is missing here. But I'll go ahead and speculate scenarios for why a math teacher would (temporarily?) prohibit multiplication by stacking [and in writing? --- nothing stops the student ...
• 341
Accepted

• 5,869
1 vote

### Is this primarily a "rote computational trick" for multiplication by 9?

In answer to the question "I've never seen this before" I knew this 'trick' with the 9x table and the one with 11x table also mentioned here when I went to primary school about 50 years ago. I will ...
1 vote

### Arguments against multiplication by 'stacking'

I've never heard of 'stacking', the method shown appears the standard way to multiply digit by digit. 37 squared. For those who wish to do this in their head, I'd go up to 40, and the same 3 down to ...

Only top scored, non community-wiki answers of a minimum length are eligible