Mental Maths worksheet with exercises on writing numbers, algebra, rounding, multiples of 9, and times tables.

Let's solve each section of this Mental Maths worksheet step by step and explain the solutions.

---

1. Writing Numbers

Convert words into numbers:

| Words | Number |
|-------|--------|
| Three thousand, two hundred & sixty | 3,260 |
| Nine thousand & forty eight | 9,048 |
| Six thousand, one hundred & nineteen | 6,119 |
| Eight hundred & seventy nine | 879 |
| Five thousand, two hundred & eleven | 5,211 |
| Five hundred & seventy four | 574 |

✔ Explanation: Simply write the number based on place values (thousands, hundreds, tens, ones).

---

2. Algebra

Solve for the missing number:

1. $ 70 + \_\_ = 150 $ → $ 150 - 70 = 80 $
→ Answer: 80

2. $ 9 \times \_\_ = 54 $ → $ 54 ÷ 9 = 6 $
→ Answer: 6

3. $ 12 \times \_\_ = 72 $ → $ 72 ÷ 12 = 6 $
→ Answer: 6

4. $ 120 - \_\_ = 50 $ → $ 120 - 50 = 70 $
→ Answer: 70

5. $ 9 \times \_\_ = 81 $ → $ 81 ÷ 9 = 9 $
→ Answer: 9

6. $ 27 + \_\_ = 51 $ → $ 51 - 27 = 24 $
→ Answer: 24

---

3. Rounding – Nearest 100

Round each number to the nearest 100:

1. 244 → Between 200 and 300; closer to 200
2. 675 → Closer to 700
3. 450 → Exactly halfway → Round up to 500
4. 822 → Closer to 800
5. 774 → Closer to 800
6. 155 → Closer to 200
7. 250 → Exactly halfway → Round up to 300
8. 350 → Exactly halfway → Round up to 400
9. 166 → Closer to 200
10. 931 → Closer to 900
11. 816 → Closer to 800
12. 750 → Exactly halfway → Round up to 800

✔ Answers:
1. 200
2. 700
3. 500
4. 800
5. 800
6. 200
7. 300
8. 400
9. 200
10. 900
11. 800
12. 800

---

4. Shade Multiples of 9

Identify which numbers in the grid are multiples of 9.

A number is a multiple of 9 if the sum of its digits is divisible by 9.

Check each number:

- 18 → 1+8=9 → ✔
- 22 → 2+2=4 → ✘
- 90 → 9+0=9 → ✔
- 900 → 9+0+0=9 → ✔
- 56 → 5+6=11 → ✘
- 55 → 5+5=10 → ✘
- 14 → 1+4=5 → ✘
- 54 → 5+4=9 → ✔
- 27 → 2+7=9 → ✔
- 13 → 1+3=4 → ✘
- 31 → 3+1=4 → ✘
- 36 → 3+6=9 → ✔
- 89 → 8+9=17 → ✘
- 81 → 8+1=9 → ✔
- 45 → 4+5=9 → ✔
- 16 → 1+6=7 → ✘
- 25 → 2+5=7 → ✘
- 38 → 3+8=11 → ✘
- 63 → 6+3=9 → ✔
- 72 → 7+2=9 → ✔
- 19 → 1+9=10 → ✘
- 99 → 9+9=18 → ✔
- 83 → 8+3=11 → ✘
- 10 → 1+0=1 → ✘
- 9 → 9 → ✔
- 30 → 3+0=3 → ✘
- 108 → 1+0+8=9 → ✔
- 80 → 8+0=8 → ✘

✔ Numbers to shade (multiples of 9):
18, 90, 900, 54, 27, 36, 81, 45, 63, 72, 99, 9, 108

---

5. Times Tables

Solve multiplication problems:

1. $ 12 × 6 = 72 $
2. $ 7 × 8 = 56 $
3. $ 9 × 6 = 54 $
4. $ 8 × 5 = 40 $
5. $ 12 × 3 = 36 $
6. $ 7 × 6 = 42 $
7. $ 12 × 4 = 48 $
8. $ 9 × 11 = 99 $
9. $ 4 × 9 = 36 $
10. $ 7 × 7 = 49 $

✔ Final Answers:
1. 72
2. 56
3. 54
4. 40
5. 36
6. 42
7. 48
8. 99
9. 36
10. 49

---

✔ Final Summary

#### Writing Numbers
- 3,260
- 9,048
- 6,119
- 879
- 5,211
- 574

#### Algebra
1. 80
2. 6
3. 6
4. 70
5. 9
6. 24

#### Rounding (nearest 100)
1. 200
2. 700
3. 500
4. 800
5. 800
6. 200
7. 300
8. 400
9. 200
10. 900
11. 800
12. 800

#### Shade Multiples of 9
Shade these:
18, 90, 900, 54, 27, 36, 81, 45, 63, 72, 99, 9, 108

#### Times Tables
1. 72
2. 56
3. 54
4. 40
5. 36
6. 42
7. 48
8. 99
9. 36
10. 49

Let me know if you'd like a printable version or a completed image!