For StudentsFor ParentsFor SchoolsSuccess StoriesOutcomesAI 100% students answered this correctly NUMBER SYSTEM 1. Natural numbers: These are the numbers (1, 2, 3, etc.) that are used for counting. 10. LCM of two or more fractions is given by: LCM of numeratorHCF of denominator 11. LCM × HCF = Product of two numbers n1 × n2 12. N = paqbrcpaqbrc, where, p, q and r are prime factors of the number n. Number of odd factors will be all possible combinations of powers of odd numbers (excluding any power of 2) 1.Divisibility by 2 or 5: A number is divisible by 2 or 5 if the last digit is divisible by 2 or 5. 2.Divisibility by 3 (or 9): All such numbers the sum of whose digits are divisible by 3 (or 9) are divisible by 3(or 9). 3. Divisibility by 4: A number is divisible by 4 if the last 2 digits are divisible by 4. 4. Divisibility by 6: A number is divisible by 6 if it is simultaneously divisible by 2 and 3. 5.Divisibility by 8: A number is divisible by 8 if the last 3 digits of the number are divisible by 8. 6. Divisibility by 11: A number is divisible by 11 if the difference of the sum of the digits in the odd places and the sum of the digits in the even places is either zero or is divisible by 11. 7. Divisibility by 12: All numbers divisible by 3 and 4 are divisible by 12. 8. Divisibility by 7, 11 or 13: The integer n is divisible by 7, 11 or 13 if and only if the difference of the number of its thousands and the remainder of its division by 1000 is divisible by 7, 11 or 13. 1. Odd × odd = odd Simplification 1. Simplification questions will be solved by VBODMAS rule. D = Division 2. To solve the approximation question, convert decimal values to the nearest values (i.e. 123.13=123, 545.18=545). LCM Formula L.C.M.= L.C.M Of NumeratorH.C.F Of Denominator Properties of LCM
LCM By Prime Factorisation 16 = 2×2 × 2× 2 12 × 16 × 24 = 2×2 × 3 × 2 × 2× 2× 2× 2 × 2 × 2 × 3 Now pairing the common prime factors we get the LCM. Hence, there are four 2’s and one 3. So the LCM of 12, 16 and 24 will be; LCM By Division Method Finding LCM of two numbers by division method is an easy method. Below are the steps to find the LCM by division method: 1. First, write the numbers, separated by commas 2. Now divide the numbers, with the smallest prime number. 3. If any number is not divisible, then write down that number and proceed further 4. Keep on dividing the row of numbers by prime numbers, unless we get the results as 1 in the complete row 5. Now LCM of the numbers will equal to the product of all the prime numbers we obtained in division method Highest Common Factor(HCF) Highest Common Factor(HCF) of two or more numbers is the greatest number which divides each of them exactly. Example : HCF of 60 and 75 = 15 because 15 is the highest number which divides both 60 and 75 exactly. How To Find HCF By Prime Factorization? The prime factorization method is also called the factor tree method. Let us understand how to find out HCF using this method with an example: HCF By Division Method Step 1: Write the given numbers horizontally, by separating them with commas. Shortcut Method To Find The HCF Of Two Numbers There is a shortcut method to find the GCD of numbers quickly. The step-by-step process on how to find HCF quickly is explained below: How To Find The HCF Of 3 Numbers? We have explained how to find the highest common factor of three numbers by using the long division method. The step-by-step process is listed below: Step 1: Calculate the HCF of the first 2 numbers. LCM And HCF Formula Product of two numbers = (HCF of the two numbers) × (LCM of the two numbers) Properties Of HCF And LCM Some important properties of HCF and LCM are as under: 1. The HCF of given numbers is never greater or more than any of the numbers. 2. The LCM of given numbers is never less than any of the numbers. 3. The HCF of two or more prime numbers is always 1. 4. The LCM of two or more prime numbers is their product. 5. The product of two numbers, a and b, is equal to the product of their HCF and LCM. It is also known as LCM and HCF formula discussed above. 6. We use the following formulas to calculate the HCF and LCM of fractions. If the sum of the digits of a number is a number that you find in the 3 times table, then the number is divisible by 3. Learn more in this video. Why is it that if the unit's digit or rightmost digit of a number is 0, then it is divisible by 10; otherwise, not? This video teaches you this in an easy an... What type of numbers do we use for counting? Do you know any other type of numbers? Let us study the different types of numbers in this video. |