Multiplication was the focus this week. Unlike subtraction, there is only one type of Multiplication. However, even though there is only one form of Multiplication there are 4 main strategies for Multiplication that students need to be aware of. Student's will need to be able to demonstrate the algorithm using materials such as place value mats or MAB blocks.
Concepts, Skills and Strategy:
Concept- To understand the Multiplication students need to be familiar with Addition as multiplication is a form of repeated addition. It is important to introduce The Set model when beginning to teach multiplication as it allows the students to gain a visual making it the easiest way for students to understand multiplication. The concept of multiplication is simple, as it is a form of repeated addition all parts are added to equal each other, it is the repeated addition of equal groups or sets. An example would be how :
4+4+4=12
same as
3 x 4 =12
4 Ways to Picture Multiplication
- The Set: 2 acorns in 3 plates. How many altogether?
- The Array: Length of a rectangle is 5cm and has a width of 3cm. What is the area?
- The Measurement/ Length Model: 4 ribbons each 2cm. How many meters?
- The Combination Model: 3 coloured shirts, 2 coloured pants. How many outfits can I make?
Skill- To be able to learn multiplication, a skill needed is to understand the basics of addition. Materials such as counters, MAB blocks and paddle pop sticks can help students learn as the ability to visual problems is a skill that is often required for children to understand. During the Children's Language Stage it may be referred to as plates of, sets of or groups of. However, as they progress and develop high order thinking skills the use of language will also change to a more mathematical way of thinking and use of language. Knowing that they have gained the skills required to move from the Children's Language Stage to the Maths Language stage having the knowledge and ability to know that Multiplied by and By both mean the same thing. As they move onto the Symbolic Language Stage they will also realise that the symbol for multiplication is represented by " x" and that multiplication is the number of groups x how many in the group they will have the skills and knowledge to do more complex multiplications as they progress.
Strategy- There are 4 strategies for Multiplication
Counting Strategy- 5 and 10, using hands to count for 5 and both hands for 10. MAB blocks can also be used for 10. Multiplication grid can also be used
Real World Strategy- Used for 0 and 1. 1 involved group, row, stack, set ( example: 1 flock of 10 sheep). Writing a number sentence and identifying a pattern. 0 used for real world situations ( example: 6 nest no egg. How many eggs did I get?)
Use Double- Used for numbers 2,4 and 8. Also known as the mental computation strategy knowing the basic double facts for addition. 2 is concept of multiplication as repeated addition. 4 uses the double double strategy and 8 uses the double x 3 strategy ( example: 6x6=12 12x12=24)
Build Up/ Down- Build up only used for 3 and 6 whereas the Build down is used for the number 9. In order to use the Build Down strategy for the number 9 the 10s fact has to be known.
Misconception:
There are 3 misconceptions when it comes to Multiplication. These are assuming multiplication will always equal a larger value, they have been taught it is repeated addition so generally they assume the result will be a larger number. Secondly, they have to multiply in the order given which is false for example 5 x13x2, if the student is. to familiar with the 2 digit multiplication they should start with 5 x2 then it will make it easy for them to multiply two of the two digit numbers together. Lastly, the incorrect use of the Order of Operations always assuming multiplication is before division students should perform in the method of which the equation appears in.
Resources:
According to the Australian Curriculum ( ACARA) students in years 3 and upwards should be able to recall multiplication facts of two, three, five and ten and to be able to relate that to division. They should also be able to represent and solve problems that involve multiplication using both mental and written strategies.
Sourced Teaching Strategy:
(https://www.homeschoolmath.net/teaching/md/multiplication_algorithm.php)
Textbook Concept, Skills and Strategy:
The concept of multiplication is developed through concrete, pictorial and symbolic representations. Children need to know the basic of all four operations but mainly addition as well as multiplication facts, using visuals or stories can help children understand what is being asked. The " think addition" strategy proves useful when it comes to multiplication. There are many strategies when it comes to multiplication the Commutativity strategy which is a key strategy in learning multiplication facts, the Skip counting strategy which is effective with the multiples of 2,5 and 10 and the Repeated addition strategy which extends on the Skip counting strategy to factors that are less than 5 ( Reys. R, 2012).
References
Jamieson-Proctor, R. (2019). Learning Environment Online: Log in to the site. Retrieved from https://leo.acu.edu.au/mod/book/view.php?id=2406568&chapterid=189998
NAP - Minimum standards - numeracy. (2016). Retrieved from https://www.nap.edu.au/naplan/numeracy/minimum-standards
Numeracy Learning Continuum. Retrieved from https://www.australiancurriculum.edu.au/media/1077/general-capabilities-numeracy-learning-continuum.pdf
Reys, R. (2017). Helping children learn mathematics (2nd ed., pp. 287, 357, 361). Milton, Qld: Wiley.