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Number facts: Multiplication and division

Number facts: Multiplication and division

Multiplication and division facts are best learned through a process of noticing patterns and relationships. Fluency of recall of number facts is important for easing the load of working memory when more complex calculations are required.

Multiplication and division facts are best learned through a process of noticing patterns and relationships.

Knowing the relationship between multiplication and division can help students.

For example, knowing that:

  • 4 \(\times\) 5 = 20 leads to 20 ÷ 4 = 5
  • 5 \(\times\) 4 = 20 leads to 20 ÷ 5 = 4.

The two-times and ten-times facts are the easiest to learn because the products are doubles and the numbers end in '-ty'. These facts can assist students to derive other facts using doubling and halving strategies.

Five-times facts are related to ten-times facts by doubling and halving.

You can view and download the Five-times slide presentation.

 

Nine-times facts can be found by taking off one set of the tens-times facts. For example, 10 is 1 more than 9 so:

  • 1 \(\times\) 9 = 1 \(\times\) 10 – 1
  • 2 \(\times\) 9 = 2 \(\times\) 10 – 2
  • 5 \(\times\) 9 = 5 \(\times\) 10 – 5.

You can view and download the Nine-times slide presentation.

 

The seven-times facts can be derived from the five-times facts using partitioning and the distributive property (e.g. 7 \(\times\) 8 = 5 \(\times\) 8 + 2 \(\times\) 8).

Using halving and doubling can assist in working out 8 \(\times\) 6 = ?

  • Half of 8 is 4.
  • 4 \(\times\) 6 = 24
  • Double the product (24) to get 48.

Students can be assisted to see patterns and relationships among the multiplication and division facts by using visual tools such as:

Yes

Yes

Name Class Section
Document Year 4: Recall multiplication facts up to 10 x 10 and related division facts Infobox 3
Document Source Infobox 3