UA · Unit 1 review

1. 1.

   Find the area of a rectangle with length 13 in and width 9 in.

   Answer. 117 square in

   A = ℓ × w = 13 × 9 = 117 square in.

2. 2.

   Find the area of the parallelogram.

   Answer. 112 square m

   A = b × h = 14 × 8 = 112 square m.

3. 3.

   A polygon is a 12-by-6 rectangle joined to a 6-by-2 rectangle. Find the total area.

   Answer. 84 square cm

   12 × 6 = 72, 6 × 2 = 12, total 84 square cm.

4. 4.

   A rectangular prism has length 4 cm, width 5 cm, and height 3 cm. Use a net (or the faces) to find the surface area.

   Answer. 94 square cm

   SA = 2(ℓw + ℓh + wh) = 2(20 + 12 + 15) = 94 square cm.

5. 5.

   Evaluate 6x + 8 when x = 2. Then Ava needs 2 of that amount. What is the total they need?

   Answer. 40

   6(2) + 8 = 12 + 8 = 20. Then multiply by 2: 40.

6. 6.

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

   Answer. 36

   2^2 = 4, then 4 × 3 = 12. Then multiply by 3: 36.

7. 7.

   Find the greatest common factor of 55 and 88. Then Luis needs 5 of that amount. What is the total they need?

   Answer. 55

   GCF(55, 88) = 11. Then multiply by 5: 55.

8. 8.

   Grace has 8 packs of 5 stickers and gives 3 stickers away. Evaluate 8 × 5 − 3 to find how many are left.

   Answer. 37

   Multiply first: 8 × 5 = 40. Then 40 − 3 = 37.

9. 9.

   Theo cuts a parallelogram with base 5 cm and height 12 cm from paper, then cuts an identical second one. What is the total paper area used?

   Answer. 120 square cm

   One parallelogram is 60 square cm. Two of them: 120 square cm.

10. 10.

    Priya is painting a triangular sail with base 8 ft and height 3 ft. How much area will the paint cover?

    Answer. 12 square ft

    A = 12 × 8 × 3 = 12 square ft.

11. 11.

    Think

    Ava found the volume 160 instead of the surface area of a 8 by 5 by 4 cm box. What is the surface area?

    Answer. 184 square cm

    Volume uses ℓwh. Surface area adds faces: 2(40 + 32 + 20) = 184 square cm.

12. 12.

    Think

    Nora tried this problem:
    Write an expression for “6 more than 2 times a number x.”
    Nora wrote 1x + 6. That is not correct. What is the right answer?

    Answer. 2x + 6

    Nora’s answer 1x + 6 is off. 2 times x is 2x; 6 more is 2x + 6.

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