L1 · Scale drawings

1. 1.

   A scale drawing uses a scale factor of 4. The original is 6 cm by 5 cm. What are the drawing’s dimensions?

   Answer. 24 cm by 20 cm

   Multiply each length by 4: 24 by 20.

2. 2.

   A scale drawing uses a scale factor of 3. The original is 8 cm by 6 cm. What are the drawing’s dimensions?

   Answer. 24 cm by 18 cm

   Multiply each length by 3: 24 by 18.

3. 3.

   A scale drawing uses a scale factor of 2. The original is 3 cm by 5 cm. What are the drawing’s dimensions?

   Answer. 6 cm by 10 cm

   Multiply each length by 2: 6 by 10.

4. 4.

   A scale drawing uses a scale factor of 4. The original is 5 cm by 5 cm. What are the drawing’s dimensions?

   Answer. 20 cm by 20 cm

   Multiply each length by 4: 20 by 20.

5. 5.

   On a map, 1 cm represents 5 km. A road is 7 cm on the map. How long is the road in kilometers? Then Nora needs 2 of that amount. What is the total they need?

   Answer. 70 km

   7 × 5 = 35 km. Then multiply by 2: 70 km.

6. 6.

   A scale drawing uses a scale factor of 3. The original is 7 cm by 4 cm. What are the drawing’s dimensions? Then Grace needs 2 of that amount. What is the total they need?

   Answer. 42 cm by 12 cm

   Multiply each length by 3: 21 by 12. Then multiply by 2: 42 cm by 12 cm.

7. 7.

   A scale drawing uses a scale factor of 2. The original is 4 cm by 5 cm. What are the drawing’s dimensions? Then Ava needs 5 of that amount. What is the total they need?

   Answer. 40 cm by 10 cm

   Multiply each length by 2: 8 by 10. Then multiply by 5: 40 cm by 10 cm.

8. 8.

   A scale drawing uses a scale factor of 2. The original is 6 cm by 6 cm. What are the drawing’s dimensions? Then Elena needs 5 of that amount. What is the total they need?

   Answer. 60 cm by 12 cm

   Multiply each length by 2: 12 by 12. Then multiply by 5: 60 cm by 12 cm.

9. 9.

   A scale drawing uses a scale factor of 5. The original is 3 cm by 4 cm. What are the drawing’s dimensions? Then Malik needs 4 of that amount. What is the total they need?

   Answer. 60 cm by 20 cm

   Multiply each length by 5: 15 by 20. Then multiply by 4: 60 cm by 20 cm.

10. 10.

    On a map, 1 cm represents 3 km. A road is 7 cm on the map. How long is the road in kilometers? Then Elena needs 4 of that amount. What is the total they need?

    Answer. 84 km

    7 × 3 = 21 km. Then multiply by 4: 84 km.

11. 11.

    Think

    Jonah tried this problem:
    A scale drawing uses a scale factor of 5. The original is 6 cm by 5 cm. What are the drawing’s dimensions?
    Jonah wrote 60 cm by 25 cm. That is not correct. What is the right answer?

    Answer. 30 cm by 25 cm

    Jonah’s answer 60 cm by 25 cm is off. Multiply each length by 5: 30 by 25.

12. 12.

    Think

    Luis tried this problem:
    A scale drawing uses a scale factor of 4. The original is 4 cm by 5 cm. What are the drawing’s dimensions?
    Luis wrote -16 cm by 20 cm. That is not correct. What is the right answer?

    Answer. 16 cm by 20 cm

    Luis’s answer -16 cm by 20 cm is off. Multiply each length by 4: 16 by 20.

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