MIA · Mixed set · Unit 1

1. 1.

   Find the area of a rectangle with length 4 m and width 7 m.

   Answer. 28 square m

   A = ℓ × w = 4 × 7 = 28 square m.

2. 2.

   Find the area of the parallelogram.

   Answer. 96 square m

   A = b × h = 8 × 12 = 96 square m.

3. 3.

   A polygon is a 6-by-3 rectangle joined to a 6-by-2 rectangle. Find the total area.

   Answer. 30 square in

   6 × 3 = 18, 6 × 2 = 12, total 30 square in.

4. 4.

   A rectangular prism has length 5 cm, width 7 cm, and height 4 cm. Use a net (or the faces) to find the surface area.

   Answer. 166 square cm

   SA = 2(ℓw + ℓh + wh) = 2(35 + 20 + 28) = 166 square cm.

5. 5.

   Evaluate 6x + 6 when x = 9. Then Priya needs 3 of that amount. What is the total they need?

   Answer. 180

   6(9) + 6 = 54 + 6 = 60. Then multiply by 3: 180.

6. 6.

   Evaluate 2^2 × 3. Then Sam needs 2 of that amount. What is the total they need?

   Answer. 24

   2^2 = 4, then 4 × 3 = 12. Then multiply by 2: 24.

7. 7.

   Find the greatest common factor of 40 and 50. Then Mei needs 2 of that amount. What is the total they need?

   Answer. 20

   GCF(40, 50) = 10. Then multiply by 2: 20.

8. 8.

   Luis has 2 packs of 8 stickers and gives 4 stickers away. Evaluate 2 × 8 − 4 to find how many are left.

   Answer. 12

   Multiply first: 2 × 8 = 16. Then 16 − 4 = 12.

9. 9.

   Sam cuts a parallelogram with base 10 m and height 9 m from paper, then cuts an identical second one. What is the total paper area used?

   Answer. 180 square m

   One parallelogram is 90 square m. Two of them: 180 square m.

10. 10.

    Mei is painting a triangular sail with base 4 ft and height 12 ft. How much area will the paint cover?

    Answer. 24 square ft

    A = 12 × 4 × 12 = 24 square ft.

11. 11.

    Think

    Owen found the volume 280 instead of the surface area of a 8 by 7 by 5 cm box. What is the surface area?

    Answer. 262 square cm

    Volume uses ℓwh. Surface area adds faces: 2(56 + 40 + 35) = 262 square cm.

12. 12.

    Think

    Grace tried this problem:
    Write an expression for “1 more than 4 times a number n.”
    Grace wrote 5n + 1. That is not correct. What is the right answer?

    Answer. 4n + 1

    Grace’s answer 5n + 1 is off. 4 times n is 4n; 1 more is 4n + 1.

Original extra practice. Keys are computed from the items, not guessed.