Number and Operation
Subitizing Subitizing is “instantly seeing how many” or in other words is the direct perceptual apprehension of the numerosity of a group (Clements, 1999). Unlike counting which focuses on the unit, subitizing focuses on the whole and unit and it underlay the number idea. There are two types of subitizing :
Perceptual Subitizing
Recognition of number without using other mathematical processes (Clements, 1999)
Conceptual Subitizing
Recognition of the number pattern as a combined part and as a whole (Clements, 1999)
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiM57wCBEQSVTO3BMxhYRE9ffbMA7mzdzLx3XqH9n0fXboTYd-YW-225KNvtYINU2iVciBA5_nOqseEATuJdfi_8Wg-1sn8KrlYxy6SPRbB_S_Hqt7QArhFziYNHmKmRJzIWCYp5n41eGG2/s320/7.jpg)
Young children will eventually able to guess the number of block being placed on the paper correctly without having to count each block using subitizing.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgvmCfj1Uukbhr9LulTRGLgW4bzNIzP8h8_7VuZo-ahnxjKxKoxGA0s-FgTM8fbikA41PqX83b6OODbCfngG1jExJUxhS8McEjcNWiO6U5VGLeEI7nzHEwY7oSBEv9QIGngDHRoPJW8iOnx/s320/8.JPG)
Example of subitizing game, the children would have to swat the fly using the fly swatter as the number on the fly appears twice. It is similar to the ‘snap’ game. This will enhance the subatizing skills of the children.
Clement (1999) says that students can use tens frames to visualize addition combinations as it will help the student to recognize the number and use the model in calculating sums.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjTVlktm5EkFI9Ti0mzlN2S776VdZTbIG421Y-kJjPSFsa8Ik_PSVEDslRS88-GQ8rLtAI8cO0z3__1Qxna9y3zn4NlcLQKJovb9KIbwiJE9shu2W14U8IHXqmXP9jL0q_9kBL0hGzHBBwl/s320/9.jpg)
‘Teddy bear race’ activity is one of the activities that use the tens frames to visualize the simple addition. The roll of the dice indicates which teddy will move one step closer to the goal. It needs 7 moves altogether for the bear to reach home. It is a simple addition of 1+1+1+1+1+1+1=7.
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Counting
According to Gelman & Gellistel (1978), there are five principles govern and define counting involved in early childhood mathematics:
One-to-one principle
-This involves the assigning of one, and only one, distinct counting word to each of the items to be counted.
Stable-order principle
-To be able to count also means knowing that the list of words used must be in a repeatable order.
Cardinal principle
-The final object in a collection represents the number of items in that collection.
Abstraction principle
-Counting tangible or non-tangible objects. children need to appreciate that they can count non-physical things such as sounds, imaginary objects or even the counting words.
Order-irrelevance principle
-This principle refers to the knowledge that the order in which items are counted is irrelevant as long as the objects in the collection are counted once and only once.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEipflKRYWyWixn9VGdGd_Hxch2bp0xkKq-8B9JjFzV3sKrDAiFiSzpMc_iRfZpquCz-JN9q57l28kM03ZZnVGaYmrBw6sQtWEOh-QPnFtAzK_2JEvAtL6u97nlM2rzNqVOETIa90Py6ovIr/s320/10.png)
Easy game on counting objects - http://www.pitara.com/activities/math/counting/index.asp
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Number word sequence
Forward number word sequence
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjx7LN3WwZCaTcfm668FRlq2tI0MIrvfMWGgS3ODtKPzjAO9jqGSLL_SgCKr2g7Im0zWdO6QTVzLLwDXSVgWyOykdLUr5rqqQiBFksE9WKkF3_-Vl6Uq-LqrZMrviy0ftWMHtHVCzzNYaXl/s320/11.jpg)
Forward number sequence starting from 1 – 10
Number word after
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjx0RJAbUO-EdYes567S8q2oq422DdEYv70VTAeAmP3y-lp-UGxMOVwqqCk8dj0_ta11sjos_j9xi69fW-BQxoTyQqhZ3k3-BeqOw4BeWVgTTBnPkhG56-iNw6PEbIt1Y0G-xZDefZ7K940/s320/12.jpg)
Q : What comes after 1
A : 2
Backward number word sequence
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhO7VIPgvEgl3DkASEbIEopxyA_sFEJEjdK1q6huYecptp1fyFkUILySD-ODKmbmLprOB9Z9VC7GcMkL2xLxnWZ90Uj7PktPmageb6caUywyEbZrtgrAiHe4rWRDfwtMji9Vzx4s1cCI4Mr/s320/13.jpg)
Backward number sequence starting from 24-15
Number word before
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEigB683yxUglYcJC64pTQ_gyVFgaZT_TKh5GacNXYGpJD4j4DW90N6i1au-G_V6qfSuYDjsgKUa4WDOe9lB8Njn5XYCG4QtNTSjPYckowzJACy_0LTvy6HNXMQB0jUTZBzcxKncHxqlS_ts/s320/14.jpg)
Q : What number comes before 16 ?
A : 17
http://www.curriculumsupport.education.nsw.gov.au/countmein/children_washing_line.html
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Number Rhymes
Simple song that helps young learner to count numbers in correct order by singing.
Number Rhymes I
One, Two
I go to school
Three, Four
I play outdoor
Five, Six
I read my books
Seven, Eight
I am never late
Nine, Ten
I sleep by then.
http://www.kidsfront.com/rhymes/number_rhymes.html
Number Rhymes II
One for the money,
And two for the show,
Three to make ready,
And four to go.
http://www.kidsfront.com/rhymes/number_rhymes.html
Reys (2009) says that addition and subtraction are inverse operations; that is, one undoes the other:
5 + 8 = 13 ---> 13 – 5 = 8 ; 10 + 15 = 25 --> 25 – 10 = 15
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg4wVVzjQLtIr9n3BJidWx-V75PxAmA8qctgSWprTB0un_dyOm98qCfblixA_FUYfIC5ULRaqUwPGgYQduNbf_ntOoWtRhZzxNMw-jiarfBksCMBCMRlDE3EuWyInTZnOnb1epZjIkX1IyL/s320/15.jpg)
Enable children to learn addition effectively using simple addition http://www.ezschool.com/Games/Addition.html
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhRJTmJ7XSr3gYrAJ_szXq1_MpQYN1dqItKfKK5CHePV7JxQNlQHqoml3NTyEqRCZThdXkgOgh3Y98QLKAOCs-VwpNoNY6nYXyWDFFZeIRtmr8Ejnfh2KkgBO6_d2btlJHeMrEY0z0gW68h/s320/16.jpg)
Simple subtraction game
http://www.primarygames.com/takeaway/question_2.htm
Multiplication can be viewed as repeated addition:
6 X 3 = 18 --> 6 + 6 + 6 + 6
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgcY6tG_kOEXNZaxB8zTBCx-fG_cfrC0hM8edJXxENmdQJWfK_-ped7xvbkl7sDn2tR-dsJVFUmKQWA3_yeZriW9HZ41DFWCWw94kmAAxxC1xRTRTFzSJqdkJqFlMFjQt8BHCH6nS1OYrJC/s320/17.jpg)
An online multiplication game, children will find this to be an interesting game of multiplication as it involves cute character and ice cream.
http://multiplication.com/flashgames/ConeCrazyLevels.htm
Division can be viewed as repeated subtraction:
32 ÷ 8 = 4 ---> 32 -8 -8 -8 -8 = 0
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhiHSVY26ttUaVvmch16_bZIgIYdgHkyZ9lfcBviu888Umvjc0VwjNQ7H2El2ixkdcigECkpGsNnxnvdrKfpUrni8PjkCcDIPXwbYK1ew2oVboJDeVG4a7dEWLohijMZ_w7FVQiiYqMP2WR/s320/18.jpg)
Dig It! is an example of division game that requires children to do a quick division to get the bone in the ground.
http://www.fun4thebrain.com/Division/dinoDigDiv.htm
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Number Facts Strategies
There are several number facts strategies that children use for addition and subtraction which are:-
Count on from larger:
9 + 50 = 50, 52, 53, 56,…59
11 + 27 = 27, 28, 29, 30,…38
Doubles:
3 + 3= 6
10 + 10 = 20
Near doubles:
12 + 13 = (12 + 12 + 1) = 25
24 + 25 = (24 + 24 + 1) = 49
Halving:
24- 12 = 12
18 – 9 = 9
Near halving:
27 - 13 = 14 = (26 - 13 = 13 + 1= 14)
17 - 8 = 9 = (16 - 8 = 8 + 1 = 9)
Bridging to 10, 100 or nearest decade or multiple of 10:
59 + 21 = 60 + 20 = 80
89 + 91 = 90 + 90 = 180
Addition and Subtraction
Tens frame could be used to teach young children about addition.
There were 3 people sitting on the ground, 3 came in, how many people were there now?
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhIGxLvofBz5hEv2ApKzzX4xka7jLhmx1OjyOk9W6QENeIKlgdnymJgyxn_LK5XvYNpzGksARWkzDzs2zBskRYeTUzI5ltXH3k87Kk5HR88Vo2oU1SIr2Rr87VoqwyA6ZODx0lIb-TYGa1a/s320/19.jpg)
By using objects with different colour to show each part of the addition, young children will quickly grasp the simple addition by adding group of the colour separately, 3 + 3 = 6 .
Same objects can be used for different operation such as subtraction, there were 6 people sitting on the ground, 3 went away, how many people were there now? 6 – 3 = 3
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg_G_SE7Mdnm3qYkVlyMqmkYb91-8vC5iY9S_qYNEi8LMc-viZAV2mWln3WNqCg3D5TXg-tUTaDXNllyczls6pcbmhw75-93sk4l8N2covrNf2d26BsMszIGg_E46-iEAmH4uriiq7ygutG/s320/20.jpg)
Two tens frame can be used if the numbers involved in the addition is greater than 10
Example from the picture, 7 white blocks + 5 blue blocks = 12 blocks
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Mental computation strategies
Docket and Perry (2002) claim that mental computation is one of the parts in young children's learning about number. It can be used as a tool to facilitate the meaningful development of mathematical concepts and skills and to promote thinking, conjecturing, and generalizing based on conceptual understanding (Reys & Barger, 1994). It includes the ability and inclination to use this understanding in flexible ways to make mathematical judgements and to develop useful strategies for handling numbers and operations.
Addition
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgC59KoIA2rSljjh-XzJnbm70lZzFQ2OlfuposmZdTUznPG2qQq0jj_JKZ4FiX7dPfem5KDxI1D94ahoRtUJ5iQevKOl535go9knKnyL8Q_AEdIAT1XaLMo79DrfUZSU0jbb7JDuRGto4-C/s320/21.jpg)
The answer is attained by adding the tens first, then followed by the units of each segment.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgOGKha2WM7Trf9Qghvc0Fgb8xXelc0dePQI3ywpYo4pgykFI-2PDgj-TmIgUJ3E4Ina_BqLSggraKvQAHj0CL-Z32_wRpK83owA_T-p7kMsupH4sp6qq-y8vkrK28QDkvWX-2IPod2gK13/s320/22.jpg)
28 + 13 = 41
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The Number Line
Young children could draw a number line and fill in the required numbers for addition or even subtraction.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgO8OatExj0s1PYhxV6NEy3kEQ_iHcN2KqMIExMSMkZVM5r_g2lp4_OGdfP1Owhi_mT6K408EG_ijY4IAxvj3yq1mpQeFQMECIRawgJoitT6u9bGcjfL3jcMbzcB5kQWNtzK2MI9XGjS2JK/s320/23.jpg)
Addition operation in number line
27 + 28 = 55
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjGsndMztbqehW7zduP8sXflq4wuAcD8n33o0TR3EN0FQNQLhW8fp6R4d7KYMxcrg1NAl7mVG4iCDiiQ3iFmF7boJKOBkMcKkuv-7WOzQLYUpLkLIpNC3ut4XLHRo-eKlTExZaqUQcVUX0s/s320/24.jpg)
Subtraction operation in number line
55 – 28 = 27
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Hundreds Chart
There are two type of this chart, 0 – 99 and 1 – 100. The 0-99 chart is usually used for subtraction while the other one is suitable to be used for addition.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgF_5rP-VtmeDTDH9m4F5nGUqrFlO005Z6FiNODu0NW5SbTZ3OrtWtGKLbXuuLs272ErBwYL7r078J3P5elI4bt9Z7OMXLn4wqVar7EPiCL4NvAoY1Ezf6ECJekpzfe1td5vjLSP7wam35n/s320/25.jpg)
0-99 chart
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiU2SHE2NEMKLNtCkEe0VsjbggpF2lUoFQSuRumIV3y6EQRT4b0ERp10LQr3gm3ts_J9x-uFn2wCm-a-9r0dpxLcc8aJgtksPmSpaMqbTwkn2NsIAFXT6xhxMtOfGckU977fEFg_C4Nv790/s320/26.jpg)
1-100 chart
How to use it?
Based on the 0-99 chart, the block is placed on the number 52. Question given by the teacher is 52 – 19.
Young children know that by moving the block 1 move upright is equal to 10 moves to the left which is equals to 52 – 10. By now they would only need to move 9 move to the left (for subtraction) to answer the question. The picture below further explained on how the operation is carried out.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgNCZQm_pM0BPq-C2vVOPD-h5mXjNit_BU2TzsWE_U6hIGQwXXOkriKiJSdxU6aM3an6fzdj9uu3BqlXdWBqF9wi9bf1ul2Vp-gXShUwrqLcHobm8Nez7rXIQ8LRICXI6MHxUMJBEcL0Zzz/s320/27.jpg)