1. WHEN is the sum of two integers a negative number? The Number System Course 2, Inquiry Lab before Lesson 3-2

2. Activity 1 Continued  The Number System In football, forward progress is represented by a positive integer. Losing yardage is represented by a negative integer. On the first play, a team lost 5 yards. On the second play the team lost 2 yards. What is the team’s total yardage on the two plays? Find out in Activity 1. Use counters to find the total yardage. Use negative integers to represent the yards lost on each play. +

3. Course 2, Inquiry Lab before Lesson 3-2 Activity 1 Continued  The Number System In football, forward progress is represented by a positive integer. Losing yardage is represented by a negative integer. On the first play, a team lost 5 yards. On the second play the team lost 2 yards. What is the team’s total yardage on the two plays? Find out in Activity 1. Use counters to find the total yardage. Combine a set of 5 negative counters and a set of 2 negative counters.

4. Course 2, Inquiry Lab before Lesson 3-2 The Number System In football, forward progress is represented by a positive integer. Losing yardage is represented by a negative integer. On the first play, a team lost 5 yards. On the second play the team lost 2 yards. What is the team’s total yardage on the two plays? Find out in Activity 1. There is a total of negative counters. The model shows that adding a negative number to another negative number results in a negative sum. So, –5 + (–2) =. The team lost a total of yards on the first two plays. Use counters to find the total yardage.

5. Course 2, Inquiry Lab before Lesson 3-2 Activity 2 Continued  The Number System The following two properties are important when modeling operations with integers. When one positive counter is paired with one negative counter, the result is called a zero pair. The value of a zero pair is 0. You can add or remove zero pairs from a mat because adding or removing zero does not change the value of the counters on the mat. Use counters to find –4 + 2. Combine negative counters with positive counters. The addends have different signs.

6. Course 2, Inquiry Lab before Lesson 3-2 Activity 2 Continued  The Number System The following two properties are important when modeling operations with integers. When one positive counter is paired with one negative counter, the result is called a zero pair. The value of a zero pair is 0. You can add or remove zero pairs from a mat because adding or removing zero does not change the value of the counters on the mat. Use counters to find –4 + 2. Remove all zero pairs. There are more negative counters than positive counters. 4 > 2

7. Course 2, Inquiry Lab before Lesson 3-2 The Number System The following two properties are important when modeling operations with integers. When one positive counter is paired with one negative counter, the result is called a zero pair. The value of a zero pair is 0. You can add or remove zero pairs from a mat because adding or removing zero does not change the value of the counters on the mat. Use counters to find –4 + 2 Find the number of counters remaining. There are negative counters remaining. So, –4 + 2 =. How would the model and sum change if the addition expression was 4 + (–2)? ________________________________________________________________ The model shows that the sum has the same sign as the greater number of counters.

8. Course 2, Inquiry Lab before Lesson 3-2 WHEN is the sum of two integers a negative number? The Number System