KS2 Primary Maths Age 13-17 - Ratio, Proportion and Algebra: Number Sequences - Explained

The video tutorial explains a mathematical rule where a number is multiplied by two and then three is added. The instructor demonstrates this rule using the number 53, resulting in 109. To find a number that precedes 25 using the same rule, the instructor reverses the operations by subtracting three and dividing by two, arriving at 11. The process is verified to ensure accuracy, and the tutorial concludes with a summary of the steps and results.

What is the result when you multiply 53 by 2 and then add 3?

• 109

• 115

• 106

• 112

If you need to find the number before 25 using the rule 'times 2, add 3', what is the first step?

• Divide by 2

• Multiply by 2

• Add 3

• Subtract 3

After subtracting 3 from 25, what is the next step to find the original number?

• Add 3

• Multiply by 2

• Divide by 2

• Subtract 3

What is the original number if the result after applying the rule 'times 2, add 3' is 25?

• 11

• 10

• 12

• 13

How can you verify the correctness of the reverse operation?

• By adding 3 and multiplying by 2

• By subtracting 3 and dividing by 2

• By multiplying by 2 and adding 3

• By dividing by 2 and subtracting 3