Choco-blocks
This is a level 3 number activity from the Figure It Out series. It is focused on using arrays to solve multiplication facts. A PDF of the student activity is included.
About this resource
Figure It Out is a series of 80 books published between 1999 and 2009 to support teaching and learning in New Zealand classrooms.
This resource provides the teachers' notes and answers for one activity from the Figure It Out series. A printable PDF of the student activity can be downloaded from the materials that come with this resource.
Specific learning outcomes:
- Use arrays to solve multiplication facts.
Choco-blocks
Achievement objectives
NA3-2: Know basic multiplication and division facts.
Required materials
- Figure It Out, Level 3, Basic Facts, "Choco-blocks", page 10
See Materials that come with this resource to download:
- Choco blocks activity (.pdf)
Activity
This activity shows students another model for multiplication, that is, that multiplication can be shown as a rectangular array. Making chocolate bar rectangles reinforces the commutative property of multiplication (a x b = b x a). This activity also shows that multiplication can be used to find the area of a rectangle. (This connects to the measurement strand.)
This activity will help students find the factors for a given product. The set of factors for 12 (1, 2, 3, 4, 6, and 12) can be found from the three different lengths of the chocolate blocks.
As an extension, you could ask students to imagine the chocolate blocks as squares and encourage them to find all square numbers from one to 100.
a. 1 x 18; 2 x 9; 3 x 6
b. 1 x 25; 5 x 5
c. 1 x 36; 2 x 18; 3 x 12; 4 x 9; 6 x 6
d. 1 x 100; 2 x 50; 4 x 25; 5 x 20; 10 x 10
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