Assorted Multiplication Rules

Multiply by 5: Multiply by 10 and divide by 2.

Multiply by 6: Sometimes multiplying by 3 and then 2 is easy.

Multiply by 9: Multiply by 10 and subtract the original number.

Multiply by 12: Multiply by 10 and add twice the original number.

Multiply by 13: Multiply by 3 and add 10 times original number.

Multiply by 14: Multiply by 7 and then multiply by 2

Multiply by 15: Multiply by 10 and add 5 times the original number, as above.

Multiply by 16: You can double four times, if you want to. Or you can multiply by 8 and then by 2.

Multiply by 17: Multiply by 7 and add 10 times original number.

Multiply by 18: Multiply by 20 and subtract twice the original number (which is obvious from the first step).

Multiply by 19: Multiply by 20 and subtract the original number.

Multiply by 24: Multiply by 8 and then multiply by 3.

Multiply by 27: Multiply by 30 and subtract 3 times the original number (which is obvious from the first step).

Multiply by 45: Multiply by 50 and subtract 5 times the original number (which is obvious from the first step).

Multiply by 90: Multiply by 9 (as above) and put a zero on the right.

Multiply by 98: Multiply by 100 and subtract twice the original number.

Multiply by 99: Multiply by 100 and subtract the original number.

Regards

10on10 Team

Free Math Worksheets - Roman Numerals

Children of class 5 are familiar with the rules that they need to follow while writing small numbers
using  Roman Numerals.  This worksheets makes a class 5 child logically understand how to write
 large numbers using Roman numerals. It also makes the child use his analytical skills and reason
out if the Roman numerals are written correctly for the Hindu- Arabic numbers.

The Romans were active in trade and commerce and from the time of learning to write they
needed a way to indicate numbers. The system they developed lasted many centuries,
and still sees some specialized use today.

Regards
10on10 Team

Interesting Triangle Facts :)

    Triangles are polygons with the least possible number of sides (three).

    The three internal angles of a triangle always add to 180 degrees.

    An equilateral triangle has three sides of equal length and three equal angles.

    An isosceles triangle has two sides of equal length and two equal angles.

    A scalene triangle has no sides of equal length and no equal angles.

    A right angle triangle has one angle that is 90 degrees.

    An obtuse triangle has one angle larger than 90 degrees.

    An acute triangle has angles that are all less than 90 degrees.

    The longest side of a right angle triangle is called the hypotenuse, it is always found opposite the right angle.

    Trigonometry is the study of the relationship between the angles of triangles and their sides.

    Triangle shapes are often used in construction because of their great strength.

Regards

10on10 Team

Free Math Worksheets for Kids - Number System

Nowadays, the South Asian numbering system, is used  in the Indian subcontinent
(comprising India, Pakistan, Bangladesh and Nepal). It  is based on the Vedic numbering system.
This system groups numbers by two places, rather than the three places which is common in most parts  of the world. The terms lakh and crore are widely used today in India and Pakistan.

In India, the South Asian numbering system is referred to as the Indian system of numbers.
In the International system of numbering, numbers are grouped in threes. Most of the business
transactions and International dealing are done using the International system of numbers.
 There is no lakh or crore in the International system instead there is million and billion.

A 5th class child can use the support of this worksheet to visually and logically understand the
relationship between the Indian and International system of numbers. There are two systems of numbering which are commonly used. They are the South Asian and International system of numbering.

Regards
10on10 Team

Free math worksheet for kids - Smallest and Largest

In one’s day to day life, a person encounters both small and large numbers.  While solving this
worksheet, a 4th class child can analyze and see the relationship between the largest 7 digit number
and smallest 8 digit number.
This worksheet also helps the child understand how to quickly find out the largest or smallest number with a specified number of digits. A 4th class child can improve his logical and analytical skills by working on this sheet.

Regards
10on10 Team

Free worksheets for kids - Predecessor

Children often get confused between the terms ‘ predecessor’ and ‘successor’.
A 3rd class child will be visually assisted in understanding the meaning of predecessor
when the child solves this worksheet. The child logically reasons out and finds out
the 2 numbers that precede the given number.  When a child  is unable to find out the predecessor
of a number mentally he can subtract 1 from the given number to find it.

Regards
10on10 Team

Amazing Math Facts :)

The numerical digits we use today such as 1, 2 and 3 are based on the Hindu-Arabic numeral system developed over 1000 years ago.

Different names for the number 0 include zero, nought, naught, nil, zilch and zip.

The smallest ten prime numbers are: 2, 3, 5, 7, 11, 13, 17, 19, 23 and 29.

2 and 5 are the only prime numbers that end with a 2 or a 5.

The golden ratio of approximately 1.618 between two quantities such as lengths often appears in nature (tree branching, uncurling ferns, pine cone arrangements etc) and has been used throughout history to create aesthetically pleasing designs and art works such as Leonardo da Vinci’s Mona Lisa.

Fibonacci numbers are named after Italian mathematician Leonardo of Pisa (better known as Fibonacci) who introduced them to Western Europe after they had earlier been described by Indian mathematicians. They are related to the golden ratio and proceed in the following order: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, .... Can you see the pattern?

The number Pi (the ratio of the circumference to the diameter of a circle) can’t be expressed as a fraction, making it an irrational number. It never repeats and never ends when written as a decimal.

Here is Pi written to 100 decimal places:tt

3.1415926535897932384626433832795028841971693993751

058209749445923078164062862089986280348253421170679

What comes after a million, billion and trillion? A quadrillion, quintillion, sextillion, septillion, octillion, nonillion, decillion and undecillion.

The name of the popular search engine ‘Google’ came from a misspelling of the word ‘googol’, which is a very large number (the number one followed by one hundred zeros to be exact).

A ‘googolplex’ is the number 1 followed by a googol zeros, a number so ridiculously big that it can’t be written because there literally isn't enough room in the entire universe to fit it in!

Check out some more big numbers.

You might have heard the word ‘infinity’ before or seen its symbol that looks like the number 8 placed on its side. Infinity means a limitless quantity or something that goes on forever. While it’s not really a number like 1, 2 or 3, infinity is often used in math as part of equations and formulas.

Regards

10on10 Team

Expanded Form

A 2nd class child will find it easy to expand a number.  Children are used to solving stereo type
problems where they don’t need to think much. When a few digits in the expanded form of
a number are missing, it will encourage the child to put on their thinking caps and find out the missing
digits.  This will ensure that the child has understood completely how to expand a number. It
will also make the child not get confused as to which digit of the number to carry over while
adding numbers.

Regards
10on10 Team

10 Math Tricks

Trick 1: Number below 10

Step1: Think of a number below 10.

Step2: Double the number you have thought.

Step3: Add 6 with the getting result.

Step4: Half the answer, that is divide it by 2.

Step5: Take away the number you have thought from the answer, that is, subtract the answer from the number you have thought.

Answer: 3

Trick 2: Any Number

Step1: Think of any number.

Step2: Subtract the number you have thought with 1.

Step3: Multiply the result with 3.

Step4: Add 12 with the result.

Step5: Divide the answer by 3.

Step6: Add 5 with the answer.

Step7: Take away the number you have thought from the answer, that is, subtract the answer from the number you have thought.

Answer: 8

Trick 3: Any Number

Step1: Think of any number.

Step2: Multiply the number you have thought with 3.

Step3: Add 45 with the result.

Step4: Double the result.

Step5: Divide the answer by 6.

Step6: Take away the number you have thought from the answer, that is, subtract the answer from the number you have thought.

Answer: 15

Trick 4: Same 3 Digit Number

Step1: Think of any 3 digit number, but each of the digits must be the same as. Ex: 333, 666.

Step2: Add up the digits.

Step3: Divide the 3 digit number with the digits added up.

Answer: 37

Trick 5: 2 Single Digit Numbers

Step1: Think of 2 single digit numbers.

Step2: Take any one of the number among them and double it.

Step3: Add 5 with the result.

Step4: Multiply the result with 5.

Step5: Add the second number to the answer.

Step6: Subtract the answer with 4.

Step7: Subtract the answer again with 21.

Answer: 2 Single Digit Numbers.

Trick 6: 1, 2, 4, 5, 7, 8

Step1: Choose a number from 1 to 6.

Step2: Multiply the number with 9.

Step3: Multiply the result with 111.

Step4: Multiply the result by 1001.

Step5: Divide the answer by 7.

Answer: All the above numbers will be present.

Trick 7: 1089

Step1: Think of a 3 digit number.

Step2: Arrange the number in descending order.

Step3: Reverse the number and subtract it with the result.

Step4: Remember it and reverse the answer mentally.

Step5: Add it with the result, you have got.

Answer: 1089

Trick 8: x7x11x13

Step1: Think of a 3 digit number.

Step2: Multiply it with x7x11x13.

Ex: Number: 456, Answer: 456456

Trick 9: x3x7x13x37

Step1: Think of a 2 digit number.

Step2: Multiply it with x3x7x13x37.

Ex: Number: 45, Answer: 454545

Trick 10: 9091

Step1: Think of a 5 digit number.

Step2: Multiply it with 11.

Step3: Multiply it with 9091.

Ex: Number: 12345, Answer: 1234512345

Regards

10on10 Team

Abacus:)

A 2nd class child is familiar with 2 digit numbers. The child will use  his visual, logical and spatial
skills in this worksheet to understand how a 3 digit number can be represented. Learning how to
represent a number using the abacus enables a child to easily understand how to add numbers
using the carry over method and subtract numbers using the borrowing method.

Regards
10on10 Team