OCSD 5th Grade Math Assessment 5.1 – Multiplication & amp ... - Free Printable

Let's solve each question step by step and explain the reasoning.

---

Question 1:

9 × □ = 36. Which is NOT a related fact?

We are given:
> 9 × □ = 36

To find the missing number:
> □ = 36 ÷ 9 = 4

So, the equation is:
> 9 × 4 = 36

Now let’s examine each option to see which one is not a related fact (i.e., not mathematically connected to this multiplication fact).

- A. 36 ÷ 4 = 9
→ This is true because 36 ÷ 4 = 9. This is a related fact (division fact). ✔

- B. 4 × 9 = 36
→ This is just the commutative property of multiplication. Same as 9 × 4 = 36. ✔

- C. 8 × 4 = 32
→ 8 × 4 = 32, which is not related to 9 × 4 = 36. This is a different multiplication fact. ✘

- D. 36 ÷ 9 = 4
→ This is the inverse operation. True and related. ✔

✔ Answer: C. 8 × 4 = 32 — This is NOT a related fact.

---

Question 2:

Which of these is NOT equivalent to 24 × 8?

We’ll compute 24 × 8 first:
> 24 × 8 = 192

Now evaluate each choice:

- A. 25 × 8 – 8
→ 25 × 8 = 200; 200 – 8 = 192 ✔ Equivalent

- B. 24 × 10 – 48
→ 24 × 10 = 240; 240 – 48 = 192 ✔ Equivalent

- C. (20 × 8) + (4 × 8)
→ 20×8 = 160; 4×8 = 32; 160 + 32 = 192 ✔ Equivalent

- D. 24 × 8 – 24
→ 24×8 = 192; 192 – 24 = 168 ✘ Not equal to 192

✔ Answer: D. 24 × 8 – 24 — This is NOT equivalent.

---

Question 3:

Mr. White bought 120 bottles of water for the football team. The water came in cases with 24 bottles per case. Which number sentence can be used to find the number of cases of water Mr. White bought?

We need to find how many cases there are if each case has 24 bottles and total bottles = 120.

This is a division problem:
> Number of cases = Total bottles ÷ Bottles per case
> = 120 ÷ 24

So the correct number sentence is:
> 120 ÷ 24 = ?

Let’s check the options:

- A. 24 × 120 = □ → This would give 2880, way too big. ✘

- B. 120 ÷ 24 = □ → This is correct! ✔

- C. 24 + □ = 102 → Doesn’t make sense here. 102 is not relevant. ✘

- D. 102 – □ = 24 → Again, unrelated numbers. ✘

✔ Answer: B. 120 ÷ 24 = □

---

✔ Final Answers:

1. C. 8 × 4 = 32
2. D. 24 × 8 – 24
3. B. 120 ÷ 24 = □

These are the correct choices based on understanding multiplication, division, and equivalent expressions.