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| =Activity - The idea of negative numbers and operations on negative numbers = | | =Activity - The idea of negative numbers and operations on negative numbers = |
| ==Objectives of the activity== | | ==Objectives of the activity== |
− | #Develop an idea that negative numbers are part of a type of numbers<br> | + | #Develop an idea that negative numbers are part of a type of numbers. |
− | #That negative numbers are continuous<br> | + | #That negative numbers are continuous. |
− | #Repesent the number line with zero as a place holder<br> | + | #Understand that positive and negative signs indicate opposite quantities. |
− | | + | #Represent the number line with zero as a place holder. |
− | | |
| ==Estimated Time== | | ==Estimated Time== |
− | This is an activity for a lesson to introduce negative numbers; can be more 2-3 period | + | This is an activity for a lesson to introduce negative numbers; can be more 2-3 periods. |
| | | |
| ==Materials/ Resources needed== | | ==Materials/ Resources needed== |
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| ==Prerequisites/Instructions, if any== | | ==Prerequisites/Instructions, if any== |
| + | Students should be familiar with the terms such as more/less, add/take away and increase/decrease. |
| + | |
| + | They should be able to compare different values, and determine greater than, less than and equal to. |
| + | |
| ==Multimedia resources== | | ==Multimedia resources== |
| ==Website interactives/ links/ simulations/ Geogebra Applets== | | ==Website interactives/ links/ simulations/ Geogebra Applets== |
| + | An interactive: [https://nrich.maths.org/content/id/5898/TugWar2.swf Tug of war] |
| + | |
| ==Process (How to do the activity)== | | ==Process (How to do the activity)== |
| Use the same example as before ([[Quantity_and_Numbers|apples and counting]]) to discuss add, take away etc. This activity is in multiple part. | | Use the same example as before ([[Quantity_and_Numbers|apples and counting]]) to discuss add, take away etc. This activity is in multiple part. |
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| ===Part 1=== | | ===Part 1=== |
| #By the previous activity we have 11 apples. Now we add a few more. Let us say we add 4 more. We have 15 apples. | | #By the previous activity we have 11 apples. Now we add a few more. Let us say we add 4 more. We have 15 apples. |
− | <b>11 + 2 = 13 ( + 2 signifies increase in apples) | + | <br>11 + 2 = 13 ( + 2 signifies increase in apples) |
| <br>13 + 2 = 15 Write the expression. Again + signifies increase | | <br>13 + 2 = 15 Write the expression. Again + signifies increase |
| #2. Let us say I ask the question – what should I add to 15 to make the number of apples 10? They will say take away Let us say we cannot use the word “take away”. <br> | | #2. Let us say I ask the question – what should I add to 15 to make the number of apples 10? They will say take away Let us say we cannot use the word “take away”. <br> |
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| *When I add (-7). I get 8. For me to get 9, I have to add a number greater than (-7) and I have added (-6). Similarly (-5) is greater than (-6). So the larger negative number is actually smaller.<br> | | *When I add (-7). I get 8. For me to get 9, I have to add a number greater than (-7) and I have added (-6). Similarly (-5) is greater than (-6). So the larger negative number is actually smaller.<br> |
| # Now we transition from numbers representing some quantities to numbers being manipulated as numbers.<br> | | # Now we transition from numbers representing some quantities to numbers being manipulated as numbers.<br> |
| + | |
| ===Part 2=== | | ===Part 2=== |
| #We have seen what negative numbers are. We will see how to work with them. <br> | | #We have seen what negative numbers are. We will see how to work with them. <br> |
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| - 3 x 1 = -3<br> | | - 3 x 1 = -3<br> |
| - 3 x 0 = 0<br> | | - 3 x 0 = 0<br> |
− | - 3 x-1 = -3<br> | + | - 3 x-1 = 3<br> |
− | - 3 x-2 = -6<br> | + | - 3 x-2 = 6<br> |
− | - 3 x-3 = -9<br> | + | - 3 x-3 = 9<br> |
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| Extend the pattern above. By simple pattern evaluation we see it is 3, 6 and 9. We have shown the number line above. It makes sense logically that the next number is 3 and that it becomes positive. The best way to extend this to division is to treat this as multiplication by fraction and extend these rules.<br> | | Extend the pattern above. By simple pattern evaluation we see it is 3, 6 and 9. We have shown the number line above. It makes sense logically that the next number is 3 and that it becomes positive. The best way to extend this to division is to treat this as multiplication by fraction and extend these rules.<br> |
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| ==Question Corner== | | ==Question Corner== |
| ==Activity Keywords== | | ==Activity Keywords== |
− | Negative numbers | + | Negative numbers<br> |
| '''To link back to the concept page''' | | '''To link back to the concept page''' |
| [[Numbers]] | | [[Numbers]] |
| + | |
| + | [[Category:Number system]] |