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Arranging oranges- A division activity ..

Escola Básica 2, 3 D. João de Portel
Portugal

Age:
8 years old

Aims:
• To use mental and written calculation strategies for the operation of division
• To solve problems by taking advantage of the relationship between multiplication and division
• To understand the meaning of the quotient and the remainder
• To understand division in the sense of measure and sharing.
• To communicate orally and in writing, using natural and mathematical language. To interpret, express and discuss results, processes and mathematical ideas.

Materials:
• Worksheet
• diced fitting , opaque bags to put pieces inside (cubes, balls, caps etc that represent oranges )
• Printer transparencies (1per group), overhead projector, or a sheet of waxed paper, alternatively and markers per group

Introduction:
Key Questions to ask: :
- What is the relationship between multiplication and division?
- What strategies will the students use? 
Main part:
- Divide the pupils into pairs
- Distribution of material ( worksheet and a sheet of A3 paper)
- Silent reading of the task carried out by the pupils
- Exploration of the task undertaken by the pupils
- Each pair presents on their A3 sheet or an acetate what they propose as a resolution of the task
- Discussion of the task in the large group

Observations:
An example of a solution.
To solve the issue associated with the first image students can use addition strategies :
Pupils add 9 repeatedly to a total of 144: 9 +9 = 18 , 18 +9 = 27 , 27 +9 = 36 , ... up to 135 +9 = 144
Pupils start adding 9 +9 = 18, 18 = 36 +18, 36 +36 = 62 alwaysusing doubles until they reach 144.
And subtraction by carrying out successive subtractions from the total number of oranges:
144-9 = 135 ; 135-9 = 126; 126-9 = 117 , ... , up to 9 -9 = 0 and counting then, how many times was9 subtracted?