Secret Code 2-3

NCTM Standards: develop fluency in adding, subtracting, multiplying, and dividing whole numbers; develop meaning for integers and represent and compare quantities with them; represent the idea of a variable as an unknown quantity using a letter or symbol; Lesson Overview: Students will use the balance to assist with solving inequalities. Skills: solving inequalities with addition, subtraction, multiplication, and division with positive and negative numbers Materials: Bossé Balance, Secret Code sheet Directions: 1. Distribute Bossé Balance and “Secret Code” sheet to each student. 2. Students will decode the numbers and solve the inequality using the balance for assistance. Once a student has solved a problem, encourage him/her to check their solutions using the balance. Extensions: • • •

use larger digits have answers come out to be in fraction form use more geometric shapes in the problems

Decode the numbers and solve the inequality using the Bossé Balance.

1 10

-2

1. N +

3. 5. N 7.

-3

-4

5

6

>

N>

7

2.

4.

8

N≥

N>

>

6. N +

N<

8. N ≥

9. N ≤

-9

10. N -

1. N + 5 > 10; N > 5

2. 6N ≥ 18; N ≥ 3

3. – 3N > 18; N < - 6

4. -4N > -24; N < 6

5. N – 1 > 5; N > 6

6. N + 5 > -9; N > -4

7. -2N < 10; N < - 5

8. N 7

9. N ≤ - 2; N ≤ 8 -4

10. N – 1 < 8; N < 9

≥ 6; N ≥ 42

>

<