Mental Math: Multiplying by 25 and 75 - Elementary Math (2024)

FAQs

What is the rule of 25 multiplication? ›

The number 25 is 100 divided by 4. So, in order to multiply by 25 what we have to do is multiply by 100 and then, divide by 4. Another trick to divide by 4 is to first divide by 2, then divide by 2 again.

When multiplying mentally, people generally like to do the bigger or important quantities first. This gives an estimate of the value expected. Such an approach is front end or left to right multiplication. Students using this method multiply the tens before the ones and hundreds before the tens and so on.

Divisibility Rule of 25

A number is divisible by 25 if the last or the final two digits of the number are divisible by 25. For example, 125 is divisible by 25 because the last two digits, 25, are divisible by 25. When a number is divisible by 25, it means that the number can be divided evenly by 25.

In this case, add 0+1 0 + 1 , then place the 1 1 in the result line. The result of 75⋅25 75 ⋅ 25 is 1875 .

In Maths, the basic explanation of multiplication is adding a number, with respect to another number, repeatedly. For example, if we are multiplying 2 by 3, that means 3 is added to itself two times, i.e. 3 + 3 = 6. This is a simple technique for kids to multiply numbers.

25 times 100 is equal to 2500.

The mathematical golden rule states that, for any fraction, both numerator and denominator may be multiplied by the same number without changing the fraction's value.

Multiply from left to right. One digit at a time. Left to right multiplication is faster because you have to remember fewer numbers to recall and use later. You will immediately start calling out the answer from the very first step of the calculation.

What is Vedic Mathematics? Vedic math is the world's fastest mental algebraic mathematics system. It was invented in India by Swami Bharati Krishna Tirtha between 1911 and 1918 and is still used today to calculate numbers rapidly.

What is the mental math method? ›

Mental math is a group of skills that allow people to do math “in their head” without using pencil and paper or a calculator. One of these skills is remembering math facts, like 8 × 5 = 40. Other skills include rounding numbers and estimating calculations.

In mathematics

25 is a square. It is a square number, being 5² = 5 × 5, and hence the third non-unitary square prime of the form p². It is one of two two-digit numbers whose square and higher powers of the number also ends in the same last two digits, e.g., 25² = 625; the other is 76.

The factors of 25 are the numbers that divide 25 exactly without leaving any remainder. As 25 is a composite number, it has many factors other than 1 and 25. Thus, the factors of 25 are 1, 5 and 25.

The answer for 24 x 24 = 576.

What are the factors and multiples of 25? The factors of 25 are 1, 5, and 25. The multiples of 25 are 25, 50, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300, etc.

5 x 5 = 25.