Let's solve each multiplication problem step by step. The task is to
multiply 3-digit multiples of 10 with
2-digit numbers.
---
🔹 Problem 1:
260 × 91
We can break this down using the distributive property:
$$
260 × 91 = 260 × (90 + 1) = (260 × 90) + (260 × 1)
$$
- $260 × 90 = 260 × 9 × 10 = (2340) × 10 = 23,400$
- $260 × 1 = 260$
Now add:
$$
23,400 + 260 = \boxed{23,660}
$$
✔ Answer: 23,660
---
🔹 Problem 2:
690 × 65
Break 65 into 60 + 5:
$$
690 × 65 = 690 × (60 + 5) = (690 × 60) + (690 × 5)
$$
- $690 × 60 = 690 × 6 × 10 = (4,140) × 10 = 41,400$
- $690 × 5 = 3,450$
Add:
$$
41,400 + 3,450 = \boxed{44,850}
$$
✔ Answer: 44,850
---
🔹 Problem 3:
950 × 15
Break 15 into 10 + 5:
$$
950 × 15 = 950 × (10 + 5) = (950 × 10) + (950 × 5)
$$
- $950 × 10 = 9,500$
- $950 × 5 = 4,750$
Add:
$$
9,500 + 4,750 = \boxed{14,250}
$$
✔ Answer: 14,250
---
🔹 Problem 4:
870 × 38
Break 38 into 30 + 8:
$$
870 × 38 = 870 × (30 + 8) = (870 × 30) + (870 × 8)
$$
- $870 × 30 = 870 × 3 × 10 = (2,610) × 10 = 26,100$
- $870 × 8 = 6,960$
Add:
$$
26,100 + 6,960 = \boxed{33,060}
$$
✔ Answer: 33,060
---
🔹 Problem 5:
530 × 28
Break 28 into 20 + 8:
$$
530 × 28 = 530 × (20 + 8) = (530 × 20) + (530 × 8)
$$
- $530 × 20 = 530 × 2 × 10 = (1,060) × 10 = 10,600$
- $530 × 8 = 4,240$
Add:
$$
10,600 + 4,240 = \boxed{14,840}
$$
✔ Answer: 14,840
---
🔹 Problem 6:
540 × 63
Break 63 into 60 + 3:
$$
540 × 63 = 540 × (60 + 3) = (540 × 60) + (540 × 3)
$$
- $540 × 60 = 540 × 6 × 10 = (3,240) × 10 = 32,400$
- $540 × 3 = 1,620$
Add:
$$
32,400 + 1,620 = \boxed{34,020}
$$
✔ Answer: 34,020
---
✔ Final Answers:
1. $260 × 91 = \boxed{23,660}$
2. $690 × 65 = \boxed{44,850}$
3. $950 × 15 = \boxed{14,250}$
4. $870 × 38 = \boxed{33,060}$
5. $530 × 28 = \boxed{14,840}$
6. $540 × 63 = \boxed{34,020}$
---
💡
Tip: Since all the first numbers are
multiples of 10, you can simplify by factoring out the zero and multiplying the remaining digits, then adding the zero back at the end. But for accuracy in multi-digit multiplication, breaking it down as shown above helps avoid mistakes.
Parent Tip: Review the logic above to help your child master the concept of 3 x 2 multiplication worksheet.
