L0 · First five days

1. 1.

   Complete the equivalent ratio: 2 : 5 = 8 : ?

   A	B
   2	5
   8	?

   Answer. 20

   Multiply both parts by 4: 5 × 4 = 20.

2. 2.

   A pack of 8 markers costs $16.64. What is the unit price per marker?

   Answer. $2.08

   $16.64 ÷ 8 = $2.08 per marker.

3. 3.

   Sam has 6 red marbles and 6 blue marbles. Write the ratio of red to blue in simplest form.

   Answer. 1 : 1

   Red : blue = 6 : 6 = 1 : 1.

4. 4.

   In Grace’s class, 7 students walk and 6 students bike. What is the part-to-whole ratio of walkers to the class, in simplest form?

   Answer. 7 : 13

   Walkers : class = 7 : 13 = 7 : 13.

5. 5.

   Are the ratios 3 : 6 and 9 : 18 equivalent? Write a complete answer — Malik will compare with a partner.

   Answer. yes

   Both simplify to 1 : 2, so they are equivalent.

6. 6.

   A pack of 10 markers costs $17.9. Theo needs 30 markers. How much will that cost at the same unit price?

   Answer. $53.7

   Unit price $1.79. 3 packs: $17.9 × 3 = $53.7.

7. 7.

   Priya has 6 red marbles and 4 blue marbles. Write the ratio of red to blue in simplest form. Write a complete answer — Nora will compare with a partner.

   Answer. 3 : 2

   Red : blue = 6 : 4 = 3 : 2.

8. 8.

   In Theo’s class, 7 students walk and 5 students bike. What is the part-to-whole ratio of walkers to the class, in simplest form? Write a complete answer — Owen will compare with a partner.

   Answer. 7 : 12

   Walkers : class = 7 : 12 = 7 : 12.

9. 9.

   Are the ratios 3 : 3 and 6 : 6 equivalent? Write a complete answer — Mei will compare with a partner.

   Answer. yes

   Both simplify to 1 : 1, so they are equivalent.

10. 10.

    A pack of 5 markers costs $6.05. Sam needs 25 markers. How much will that cost at the same unit price?

    Answer. $30.25

    Unit price $1.21. 5 packs: $6.05 × 5 = $30.25.

11. 11.

    Think

    Mei tried this problem:
    Priya has 2 red marbles and 7 blue marbles. Write the ratio of red to blue in simplest form.
    Mei wrote 4 : 7. That is not correct. What is the right answer?

    Answer. 2 : 7

    Mei’s answer 4 : 7 is off. Red : blue = 2 : 7 = 2 : 7.

12. 12.

    Think

    Sam tried this problem:
    In Nora’s class, 5 students walk and 3 students bike. What is the part-to-whole ratio of walkers to the class, in simplest form?
    Sam wrote 10 : 8. That is not correct. What is the right answer?

    Answer. 5 : 8

    Sam’s answer 10 : 8 is off. Walkers : class = 5 : 8 = 5 : 8.

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