L0 · First five days

1. 1.

   Find the area of a rectangle with length 7 in and width 3 in.

   Answer. 21 square in

   A = ℓ × w = 7 × 3 = 21 square in.

2. 2.

   Compute 23 × 14. Write the product in simplest form.

   Answer. 16

   23 × 14 = 212 = 16.

3. 3.

   Evaluate 5 × 7 − 5.

   Answer. 30

   Multiply first: 5 × 7 = 35. Then 35 − 5 = 30.

4. 4.

   Find 5.7 × 2.

   Answer. 11.4

   5.7 × 2 = 11.4.

5. 5.

   Evaluate 4 + 6 × 4. Then Malik needs 3 of that amount. What is the total they need?

   Answer. 84

   Multiply first: 6 × 4 = 24. Then 4 + 24 = 28. Then multiply by 3: 84.

6. 6.

   Priya is covering 2 identical bulletin boards. Each is 25 cm by 3 cm. What total area must be covered?

   Answer. 225 square cm

   One area is 115. 2 of them: 115 × 2 = 225 square cm.

7. 7.

   A pan is 68 full of brownies. Jonah eats 23 of what is in the pan. How much of a whole pan did Jonah eat?

   Answer. 12

   68 of a pan, then 23 of that: 68 × 23 = 12.

8. 8.

   Elena has 8 packs of 4 stickers and gives 1 stickers away. Evaluate 8 × 4 − 1 to find how many are left.

   Answer. 31

   Multiply first: 8 × 4 = 32. Then 32 − 1 = 31.

9. 9.

   Find 7.6 × 3. Then Priya needs 5 of that amount. What is the total they need?

   Answer. 114

   7.6 × 3 = 22.8. Then multiply by 5: 114.

10. 10.

    Evaluate 3 + 6 × 4. Then Mei needs 4 of that amount. What is the total they need?

    Answer. 108

    Multiply first: 6 × 4 = 24. Then 3 + 24 = 27. Then multiply by 4: 108.

11. 11.

    Think

    Theo found the area of a 75 by 4 cm rectangle by adding 75 + 4. What is the actual area?

    Answer. 535 square cm

    Adding gives perimeter pieces, not area. A = ℓ × w = 75 × 4 = 535 square cm.

12. 12.

    Think

    Owen computed 78 × 58 by adding and got 112. What is the actual product in simplest form?

    Answer. 3564

    Multiply numerators and denominators, then simplify: 3564 = 3564.

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