7th Grade Math

Use counters to find - 4 + 2.

Combine 4 negative

counters with 2 positive

counters.

Remove all zero pairs.

Find the number of

counters remaining. -

So, - 4 + 2 = - 2.

and Apply

Use counters or a drawing to find each sum.

1. 5 + 6 2. - 3 + (-5) 3. - 5 + (-4)


2. 7 + 3 5. - 2 + (-5) 6. - 8 + (-6)


3. 
   
   
   
   • 6 + 5 8. 3 + (-6) 9. - 2 + 7
   
   
   
   


4. 8 + (-3) 11. - 9 + 1 12. - 4 + 10

the Results

13. Write two addition sentences where the sum is positive. In each sentence,
    one addend should be positive and the other negative.


14. Write two addition sentences where the sum is negative. In each sentence,
    one addend should be positive and the other negative.


15. Write two addition sentences where the sum is zero. Describe the numbers.


16. GAME SHOWS A contestant has -350 points after the first two rounds of
    questions. What is his point standing after earning 500 points in the third
    round of questions?

1 7. MAKE A CONJECTURE What is a rule you can use to find the sum of two integers

with the same sign? two integers with different signs?

Lesson 2A Add and Subtract Integers 87

086_098_C2L2_895130.indd 87 12/29/09 4:00 PM