Work out 74 × 58
Worked Solution & Answer
74 × 50 = 3700 M1
74 × 8 = 592
3700 + 592 = 4292 A1
74 × 8 = 592
3700 + 592 = 4292 A1
Answer: 4292
Multiplication — Notes & Worked Examples Show / Hide
Explanation:
For long multiplication, multiply the top number by the units digit first, then put a placeholder 0 in the units column on the second row before multiplying by the tens digit. Add the two rows together carefully to get the final product.
To multiply decimals, ignore the decimal points at first and multiply the whole numbers. Count the total number of digits after the decimal point in the original question, and place the decimal point in your answer so it has the exact same number of decimal places.
Example 1: Work out 347 × 26
Solution:
| 3 | 4 | 7 | ||
| × | 2 | 6 | ||
| 2 | 0 | 8 | 2 | |
| + | 6 | 9 | 4 | 0 |
| 9 | 0 | 2 | 2 |
Row 1: 347 × 6 = 2082
Row 2: Put 0, then 347 × 2 = 6940
Add rows: 2082 + 6940 = 9022
Answer: 9022
Example 2: Work out 4.8 × 0.35
Solution:
Step 1: Remove decimals → work out 48 × 35
• 48 × 5 = 240 and 48 × 30 = 1440
• 240 + 1440 = 1680
Step 2: Count decimal places in the question:
• 4.8 (1 d.p.) and 0.35 (2 d.p.) → 3 d.p. in total
• 1680 with 3 d.p. is 1.680 = Answer: 1.68
Work out 23 × 15
Worked Solution & Answer
Work out 76 × 24
Answer
Worked Solution & Answer
Using standard column multiplication: M1
76 × 4 = 304 M1
76 × 20 = 1520
304 + 1520 = 1824 A1
76 × 4 = 304 M1
76 × 20 = 1520
304 + 1520 = 1824 A1
Answer: Answer 1824
Work out 247 × 63
Worked Solution & Answer
247 × 3 = 741 M1
247 × 60 = 14 820 M1
741 + 14 820 = 15 561 A1
247 × 60 = 14 820 M1
741 + 14 820 = 15 561 A1
Answer: 15 561
Work out 1.35 × 48
Worked Solution & Answer
135 × 48: 135 × 40 = 5400 M1
135 × 8 = 1080 M1
5400 + 1080 = 6480
Since 1.35 has 2 decimal places: 64.80 = 64.8. A1
135 × 8 = 1080 M1
5400 + 1080 = 6480
Since 1.35 has 2 decimal places: 64.80 = 64.8. A1
Answer: 64.8
Work out 273 × 54
Worked Solution & Answer
273 × 4 = 1092 M1
273 × 50 = 13 650 M1
13 650 + 1092 = 14 742 A1
273 × 50 = 13 650 M1
13 650 + 1092 = 14 742 A1
Answer: 14 742
(a) (i) Work out the exact value of 2· 8 + 3· 58.
(ii) Write your answer correct to 2 decimal places.
(b) Harvey has used his calculator to work out that 23 × 56 = 1288.
Without using multiplication, what calculation could he do to check that this answer is correct?
(ii) Write your answer correct to 2 decimal places.
(b) Harvey has used his calculator to work out that 23 × 56 = 1288.
Without using multiplication, what calculation could he do to check that this answer is correct?
(a) Work out the exact value of 2· 8 + 3· 58. [1 mark]
(b) Write your answer correct to 2 decimal places. [1 mark]
(b) Harvey has used his calculator to work out that 23 × 56 = 1288.
Without using multiplication, what calculation could he do to check that this answer is correct? [1 mark]
Without using multiplication, what calculation could he do to check that this answer is correct? [1 mark]
Worked Solution & Answer
(a)
(2.8 + 3.5) / 8 = 6.3 / 8 = 0.7875. B1
Answer (a): 0.7875
(b)
0.7875 rounded to 2 d.p. is 0.79. B1
Answer (b): 0.79
(b)
Use the inverse operation: divide 1288 by 23 or 56. B1
Answer (b): 1288 ÷ 23 (= 56) or 1288 ÷ 56 (= 23)
Work out 0.37 × 0.26
Give your answer as a decimal.
Give your answer as a decimal.
Answer
Worked Solution & Answer
37 × 26 = 37 × 20 + 37 × 6 = 740 + 222 = 962 M2
0.37 has 2 decimal places and 0.26 has 2 decimal places (total 4 decimal places). M1
0.0962 A1
0.37 has 2 decimal places and 0.26 has 2 decimal places (total 4 decimal places). M1
0.0962 A1
Answer: Answer 0.0962
Here is a multiplication table.
Use the table to answer the following questions.
(a) Work out 3843 ÷ 63 [1 mark]
Answer
(b) Work out 6.1 × 6.7 [1 mark]
Answer
(c) Work out 63 × 66 [2 marks]
Answer
Worked Solution & Answer
(a)
From table, 61 × 63 = 3843, so 3843 ÷ 63 = 61 B1
Answer (a): Answer 61
(b)
61 × 67 = 4087 ⇒ 6.1 × 6.7 = 40.87 B1
Answer (b): Answer 40.87
(c)
63 × 66 = 63 × 65 + 63 = 4095 + 63 = 4158 M1 A1
Answer (c): Answer 4158
Here is a calculation.
31 × 84 = 2604
You can use the calculation to help answer the following questions.
31 × 84 = 2604
You can use the calculation to help answer the following questions.
(a) Work out 2604 ÷ 84 [1 mark]
Answer
(b) Work out 3.1 × 8.4 [1 mark]
Answer
(c) Work out 31 × 85 [2 marks]
Answer
Worked Solution & Answer
(a)
2604 ÷ 84 = 31 B1
Answer (a): Answer 31
(b)
3.1 × 8.4 = 2604 ÷ 100 = 26.04 B1
Answer (b): Answer 26.04
(c)
31 × 85 = 31 × 84 + 31 = 2604 + 31 = 2635 M1 A1
Answer (c): Answer 2635