Mental Maths Practise Year 5 Worksheets - Free Printable

Let's solve each question in the Mental Maths Quiz 5:6 step by step and explain the reasoning.

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1) 540 ÷ 6

Divide 540 by 6:

$$
540 ÷ 6 = 90
$$

✔ Answer: 90

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2) Write down a multiple of 7 between 40 and 50.

List multiples of 7:
- 7, 14, 21, 28, 35, 42, 49, 56...

Between 40 and 50: 42 and 49

✔ Answer: 42 or 49 (either is acceptable)

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3) 28.6 × 100

Multiplying by 100 moves the decimal point two places to the right:

$$
28.6 × 100 = 2860
$$

✔ Answer: 2860

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4) The radius of a circle is 6.5 cm. What is the diameter?

Diameter = 2 × Radius

$$
2 × 6.5 = 13 \text{ cm}
$$

✔ Answer: 13 cm

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5) In a spelling test, the scores are 15, 8, 11, 16, 10, 5 and 10. What is the range?

Range = Highest score − Lowest score

- Highest: 16
- Lowest: 5
- Range = 16 − 5 = 11

✔ Answer: 11

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6) What is this part of the circle called?

(Shaded region from center to arc — like a "slice")

Options: chord, radius, circumference, sector

This shaded area is bounded by two radii and an arc → it's a sector

✔ Answer: sector

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7) Add up ⅖, ¾₀ and ½. Give your answer as a mixed number.

First, convert all fractions to have a common denominator.

Fractions:
- ⅖ = 12/20
- ¾₀ = 3/40
- ½ = 20/40

Wait, better to use LCM of denominators: 20, 40, 2 → LCM is 40

Convert:
- ⅖ = (2×8)/(5×8) = 16/40
- ¾₀ = 3/40
- ½ = 20/40

Now add:
$$
16/40 + 3/40 + 20/40 = 39/40
$$

39/40 is less than 1 → not a mixed number yet.

But wait — did we misread?

Wait: ⅖ + ¾₀ + ½

Wait: ¾₀ = 3/40? Yes.

So:
- ⅖ = 16/40
- 3/40 = 3/40
- ½ = 20/40

Sum = 16 + 3 + 20 = 39/40

But 39/40 is less than 1, so it's just a proper fraction.

But the question says "give your answer as a mixed number".

That suggests maybe there’s a typo? Or perhaps I misread the fractions.

Wait: Is it ⅖, ¾₀, and ½?

Yes.

So sum = 16/40 + 3/40 + 20/40 = 39/40 → still less than 1.

But that can't be a mixed number unless it's improper.

Wait — could it be ⅖, 3/10, and ½?

Ah! Maybe it's ⅖, 3/10, and ½ — but written as ¾₀? That might be a formatting issue.

"¾₀" likely means 3/10, not 3/40.

Because ¾₀ looks like 3 over 10.

So probably: ⅖, 3/10, and ½

Let’s assume that: ⅖, 3/10, ½

Find LCD of 5, 10, 2 → LCM = 10

Convert:
- ⅖ = 4/10
- 3/10 = 3/10
- ½ = 5/10

Add: 4 + 3 + 5 = 12/10 = 1 2/10 = 1 1/5

✔ Answer: 1 1/5

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8) Which two numbers have a sum of 11 and a product of 28?

Let the numbers be x and y.

x + y = 11
x × y = 28

Try pairs that add to 11:
- 1 & 10 → 1×10 = 10 ✘
- 2 & 9 → 18 ✘
- 3 & 8 → 24 ✘
- 4 & 7 → 28 ✔

So: 4 and 7

✔ Answer: 4 and 7

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9) Which fraction is equivalent to 1/3?

Options:
⅜, ⅜, ⁴⁄₁₀, ²⁄₇, ³⁄₉

Check each:
- ⅜ = 0.375 ≠ 0.333...
- ⅜ = same
- ⁴⁄₁₀ = 0.4 ✘
- ²⁄₇ ≈ 0.2857 ✘
- ³⁄₉ = 1/3 ✔ (because 3÷3 = 1, 9÷3 = 3)

✔ Answer: ³⁄₉

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10) 578 ÷ 10

Dividing by 10 moves decimal one place left:

$$
578 ÷ 10 = 57.8
$$

✔ Answer: 57.8

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11) Write down 7:20pm as a 24-hour clock time.

PM → add 12 to hours

7:20 PM = 19:20

✔ Answer: 19:20

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12) Milly and Molly's ages add up to 19 years. Milly is 3 years older than Molly. How old are they?

Let Molly's age = x
Then Milly's age = x + 3

Sum: x + (x + 3) = 19
→ 2x + 3 = 19
→ 2x = 16
→ x = 8

So Molly is 8, Milly is 11

✔ Answer: Milly is 11, Molly is 8

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13) Mandy is 67 inches tall. She is ___ ft ___ inches tall. (12 inches = 1 foot)

Divide 67 by 12:

- 12 × 5 = 60
- 67 − 60 = 7

So: 5 feet 7 inches

✔ Answer: 5 ft 7 inches

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**14) Frazer buys a 6 multi-pack bag of crisps for £2.40.

Quadra buys 6 single packs of crisps for 45p each.
How much more did Quadra spend on her crisps?**

Frazer: £2.40 for 6 packs

Quadra: 6 × 45p = 270p = £2.70

Difference: £2.70 − £2.40 = £0.30

✔ Answer: £0.30 (or 30p)

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15) Tyger throws the ball 3.58m and Frazer throws it 380cm. Who throws further? By how many?

Convert both to same unit.

380 cm = 3.80 m (since 100 cm = 1 m)

Compare:
- Tyger: 3.58 m
- Frazer: 3.80 m

So Frazer threw further.

Difference: 3.80 − 3.58 = 0.22 m

Or 22 cm

✔ Answer: Frazer throws further by 0.22 m (or 22 cm)

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16) A third of a number is 21. What is the number?

Let the number be x.

$$
\frac{1}{3}x = 21
$$

Multiply both sides by 3:

$$
x = 21 × 3 = 63
$$

✔ Answer: 63

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✔ Final Answers Summary:

| Q | Answer |
|---|--------|
| 1 | 90 |
| 2 | 42 or 49 |
| 3 | 2860 |
| 4 | 13 cm |
| 5 | 11 |
| 6 | sector |
| 7 | 1 1/5 |
| 8 | 4 and 7 |
| 9 | ³⁄₉ |
| 10 | 57.8 |
| 11 | 19:20 |
| 12 | Milly: 11, Molly: 8 |
| 13 | 5 ft 7 inches |
| 14 | £0.30 |
| 15 | Frazer by 0.22 m (or 22 cm) |
| 16 | 63 |

Let me know if you'd like this formatted as a printable answer sheet!