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Return to HintPracticeExample 7-4bInteger Interactive

Adding Integers: Color Chips

49Rememberkeep, change, changeGraphic OrganizerIf the problem is subtraction, change subtraction to adding the opposite and then follow the addition rule.PracticeExample 7-4bVocabulary

Opposite Numbers numbers that are the same distance from zero in the opposite direction

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What is the Opposite, or Additive Inverse, of a Number?

Click to WatchVideoExample 7-4bVocabulary

Integers Integers are all the whole numbers and all of their opposites on the negative number line including zero.-7opposite7

6Example 7-4bVocabularyZero Pairs: A pair of numbers whose sum is zeroMath Minute

73 + 6 = 9

Adding IntegersWe can use positive & negative charges to help us add integers.

3 + (- 4) = - 1

Adding Integers

(-3 )+ 4 = 1

Adding Integers

-5 +-2 = -7

Adding Integers

Adding Integer Practice

Click the Work Mat to begin practicing adding integers.Example 7-4bGraphic Organizer

13Example 7-4bSubtraction

There is just 1 Simple Rule for subtracting integers.Add the Opposite!(Keep-change-change) animation

145 - 2 = 3

5 + -2 = 3

Subtracting IntegersKeepChangeChange

2 - 5 = -3

2 + -5 = -3

Subtracting IntegersChange to Addition

Adding & Subtracting Integers Practice

Click the Work Mat to begin practicing adding & subtracting integers.

How Do You Add Integers Using a Number Line?

Time to watch TV.Click the TV to Watch the VideoAdding integersWe can use a number line to help us add positive and negative integers.2 + 5 =

-23= 3Start at zeroGo to first numberMove in the direction and distance of the second numberExample 1:

19How can we use the number line to work out 2 + 5?Start at 2 and count forwards 5 units. On a number line we move to the right for forwards (in a positive direction) and to the left for backwards (in a negative direction).Explain that the answer can be positive or negative depending on the starting point. It is important to stress this fact because when pupils learn the rules for multiplying and dividing negative numbers they often confuse these rules for the rules for addition and subtraction. Example 2:3 + 4 == 7

-3-7Adding integersStart at zeroGo to first numberMove in the direction and distance of the second number

20How can we use the number line to work out 3 + -4?Explain that when we add a negative number we have to move backwards down the number line. The answer can be positive or negative depending on the starting point. Stress that adding a negative number is equivalent to subtracting the positive value of that number.

5-3Subtracting integersWe can use a number line to help us subtract positive and negative integers.5 8 == 35 + (-8) == 3>Example: 15 8 5 + (- 8) is the same as

21How can we use the number line to work out 5 8?Start at 5 (click to make the 5 orange) and count backwards 8.

3 6 =

39= 9Example: 23 6is the same as3 + 6Subtracting integers3 + 6 == 9>

22How can we use the number line to work out 3 6?Many pupils may find this difficult to understand. Explain what is happening.When we subtract 6 we move backwards down the number line, so, when we subtract -6 we need to move forwards up the number line.3 6 is equivalent to 3 + 6Yow may wish to give further examples of double negatives being equivalent to positives.Lets PracticeClick on the correct answer.1. -6 + 3 =a. 3b. -3c. 8d. -8Rememberkeep, change, changeGraphic OrganizerIf the problem is subtraction, change subtraction to adding the opposite and then follow the addition rule.Practice