california standards
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California Standards. NS2.3 Solve addition, subtraction, multiplication, and division problems, including those arising in concrete situations, that use positive and negative integers and combinations of these operations. Also covered: AF1.2. - PowerPoint PPT PresentationTRANSCRIPT
Holt CA Course 1
2-2 Adding Integers
NS2.3 Solve addition, subtraction, multiplication, and division problems, including those arising in concrete situations, that use positive and negative integers and combinations of these operations.Also covered: AF1.2
California Standards
Holt CA Course 1
2-2 Adding Integers
Use a number line to find the sum.
Additional Example 1A: Modeling Integer Addition
2 –14 –12 –10 –8 –6 –4 –2 0
–7 + (–4)–7+(–4)
–7 + (–4) = –11
Start at 0. Move left 7 units. Then move left4 more units.
Holt CA Course 1
2-2 Adding Integers
Use a number line to find the sum.
Additional Example 1B: Modeling Integer Addition
–12 + 19
–12
19
–12 + 19 = 7
Start at 0. Move left 12 units. Then move right 19 units.
2 4 6 8
–12 –10 –8 –6 –4 –2 0
Holt CA Course 1
2-2 Adding Integers
Adding IntegersAdding Integers
To add two integers with the same sign, find the sum of their absolute values. Use the sign of the two integers.
To add two integers with different signs, find the difference of their absolute values. Use the sign of the integer with the greater absolute value.
Holt CA Course 1
2-2 Adding Integers
Find the sum.
Additional Example 2A: Adding Integers Using Absolute Values
–4 + 8
–4 + 8
The signs are different. Find the difference of the absolute values.
Think: 8 – 4 = 4.
Use the sign of the integer with the greater absolute value.
4
When adding integers, think: if the signs are the same, find the sum. If the signs are different, find the difference.
Helpful Hint
Holt CA Course 1
2-2 Adding Integers
Additional Example 2B: Adding Integers Using Absolute Values
Find the sum.
23 + (–35)
23 + (–35)
The signs are different. Find the difference of the absolute values.
Think: 35 – 23 = 12.
Use the sign of the integer with the greater absolute value (negative).
–12
Holt CA Course 1
2-2 Adding Integers
Evaluate x + y for x = –42 and y = 71.
Additional Example 3: Evaluating Expressions with Integers
x + y
–42 + 71
Substitute for –42 for x and 71 for y.
The signs are different. Think: 71 – 42 = 29
Use the sign of the integer with the greater absolute value (positive).29
Holt CA Course 1
2-2 Adding Integers
The jazz band’s income from a bake sale was $286. Expenses were $21. Use integer addition to find the band’s total profit or loss.
Additional Example 4: Application
286 + (–21)
286 – 21
265
The band's profit was $265.
Use negative for the expenses.
Find the difference of the absolute values.
The answer is positive.
Holt CA Course 1
2-2 Adding Integers
Check It Out! Example 1
Use a number line to find the sum.
2 –14 –12 –10 –8 –6 –4 –2 0
–4 + (–5)–4+(–5)
–4 + (–5) = –9
Start at 0. Move left 4 spaces. Then move left5 more spaces.
Holt CA Course 1
2-2 Adding Integers
Check It Out! Example 2
Find the sum.
–13 + (–24)
–13 + (–24)
The signs are the same. Find the sum of the absolute values.
Think: 13 + 24 = 37.
Use the sign of the two integers.–37
Holt CA Course 1
2-2 Adding Integers
Check It Out! Example 3
Evaluate x + y for x = –24 and y = 17.
x + y
–24 + 17
Substitute for –24 for x and 17 for y.
The signs are different. Think: 24 – 17 = 7.
Use the sign of the integer with the greater absolute value (negative).
–7
Holt CA Course 1
2-2 Adding Integers
Check It Out! Example 4
The French Club was raising money for a trip to Washington, D.C. Their car wash raised $730. They had expenses of $52. Use integer addition to find the club’s total profit or loss.
730 + (–52)
730 – 52
678
The club's profit was $678.
Use negative for the expenses.
Find the difference of the absolute values.
The answer is positive.