The Transport Museum - Class 4 Free MCQ Test with solutions

The correct product of multiplying 30 by 50 is 1500. Here's a step-by-step breakdown:

• First, multiply the single digits: 3 and 5 to get 15.
• Add the zeros from 30 and 50 to the result, which gives you 1500.
• Therefore, the correct product is 1500.

Using the splitting method, write 15 as 10 + 5 so that n × 15 = (n × 10) + (n × 5). Checking each option:

• 4 × 15 = (4 × 10) + (4 × 5) = 40 + 20 = 60
• 5 × 15 = (5 × 10) + (5 × 5) = 50 + 25 = 75
• 10 × 15 = (10 × 10) + (10 × 5) = 100 + 50 = 150
• 3 × 15 = (3 × 10) + (3 × 5) = 30 + 15 = 45

Option c is incorrect because it was miswritten as (10 × 5) + (10 × 5) = 100, which does not equal 150.

When multiplying a number by 200, it is effectively the same as multiplying it by 2 and then adding two zeros. For instance, multiplying 1 by 200 results in 200. 

When you multiply a number by 10, it has a straightforward effect:

• The number shifts one place to the left in the decimal system.
• This shift adds a zero to the end of the number.
• For instance, multiplying 5 by 10 results in 50, showing the value increases by a factor of ten.

The pattern in the times-15 table is that each number increases by 15 from the previous one. This pattern can be observed by:

• Starting with an initial number, such as 0 or 15.
• Adding 15 to each subsequent number.
• Continuing this pattern leads to a sequence where each number is 15 more than the last.

When multiplying 12 by 20, it can be visualized as 12 × 2 Tens, which equals 24 Tens. Thus, 24 Tens translates to 240.

First, calculate 13 × 10 = 130.

Then, calculate 13 × 5 = 65.

Add the two results: 130 + 65 = 195.

To calculate 11 × 200, use the pattern of multiplying by hundreds.

First, express 200 as 2 × 100.

So, the problem becomes: 11 × (2 × 100).

This can be simplified to: (11 × 2) × 100.

Calculate 11 × 2 to get 22.

Finally, multiply 22 × 100 to get 2200.

Each bicycle has 2 wheels.

To find the total number of wheels on 15 bicycles:

Multiply the number of bicycles by the number of wheels per bicycle:

15 bikes × 2 wheels = 30 wheels.

The original number is multiplied by 100.

• Multiplying by 100 adds two zeros to the number.
• For example, multiplying 5 by 100 gives 500.

Therefore, the correct answer is two zeros.