Abhyas

Practise makes perfect

Math Facts MathExercises Olympiad Math Class 4 Unified International Mathematics Olympiad

Number Divisibility Rules

Divisibility Rules of whether a number is divisible by 2, 3, 4, 5, 6, 8, 9 and 10

NumberRuleExample
2Last digit in the number is even.14, 102, 118, 560
all end in even numbers, so all are divisible by 2.
3Sum of the digits of the number is divisible by 3.
The sum of the digits of 396 is 3+9+6 = 18 which is
divisible by 3, so 396 is divisible by 3.
4Number formed by the last 2 digits is divisible by 4.Last 2 digits of 1424 is 24, which is divisible by
4, so 1424 is divisible by 4.
5Last digit is 0 or 535, 90, 475
6Number is even and divisible by 3.144 is even and is divisible by 3 (sum of digits 1+4+4 = 9, divisible by 3), so 144 is divisible by 6.
8Last 3 digits divisible by 8 or Last 3 digit is 000Last 3 digits of 83400 is 400 which is divisible by 8. Last 3 digits of 1000 is 000 hence it is divisible by 8
9Sum of the digits of the number is divisible by 9.Sum of the digits of 1485 is 1+4+8+5 = 18
which is divisible by 9, so 1485 is divisible by 9
10Last digit is 090, 120, 680
Number Divisibility Rules

Problems on Divisibility

1. Determine the following numbers which are divisible by 2, using the test of divisibility by 2:

(i) 176, (ii) 221, (iii) 327, (iv) 90, (v) 192

2. Let us consider the following numbers to find whether the numbers are divisible or not divisible by 3:

(i) 176, (ii) 221, (iii) 327, (iv) 90, (v) 192

 3. Is 7248 is divisible (i) by 4, (ii) by 2 and (iii) by 8?

4. Without actual division, find if 235932 is divisible (i) by 4 and (ii) 8.

5. Determine which of the following numbers which are divisible by 6, using the test of divisibility by 6: 42, 144, 180, 258, 156

6. Determine which of the following numbers which are divisible by 9, using the test of divisibility by 9: 

99, 198, 171, 9990, 3411.

Competitive Exams Math Facts MathExercises Mental Ability National Level Science Talent Search Unified Council Olympiad Unified Cyber Olympiad Preparation Unified International Mathematics Olympiad

Mental Ability – Competitive Exam Preparation – Number Series by adding fixed number – NTSE, NCO, NSO, IMO and other Competitive Exams

Mental Ability – Competitive Exam Preparation – Number Series by adding fixed number – NTSE, NCO, NSO, IMO and other Competitive Exams

The sequence or series of numbers created by adding fixed number :

  1. 5 , 7 , 9 , 11 , 13 etc – Number sequence obtained by adding fixed number 2
  2. 6, 11, 16, 21, 26 etc – Number sequence obtained by adding fixed number 5

Similarly number sequence can be obtained by adding two fixed numbers alternatively or by adding two fixed numbers after repeated series. Example below:

5, 7, 10,12, 15, 17, 20 etc – This number sequence is formed by adding 2 and 3 alternatively

5, 6, 7, 9, 11, 13, 16, 19, 22 etc – This number sequence is formed by adding fixed number 1 , 2 and 3 after regular interval i.e after 3 numbers

Below is some questions to practise this. Please leave your answers in comment box on this page or write to us on abhyas.practise@gmail.com.

We will revert back with right answers at the earliest

Complete the sequence by adding fixed numbers

  1. 1234, 1236, 1238, _____, 1242, 1244, _____
  2. 1400, 1500, ______ , 1700, 1800, 1900, ______
  3. 3, 9, 15, _____, 27, 33, 39, ______, 51
  4. 8, 17, _____, 35, 44, _____, 62
  5. 10, 15, 25, 35, 40, 45, 55, 65, _____ , 75, 85, ______
  6. 6, 9, 15, 21, 24, 27, 33, ______ , 42, ______
  7. 3, 5, 7, 10, 13, 16, 18, 20, _____, 25, ______, 31
  8. 10, 20, 50, _____, 90, 100, 130, 160, _____, 180, 210, 240
  9. 1000, 1200, 1600,________, 2200, 2400, 2800, 3200
  10. 86, 96, 116, 136, 166, ______, 236, 276, 326, 376

Please like and share this post if you like this page.

Math Cheatsheet Uncategorized

Real Numbers Types – Rational and Irrational – Math Cheatsheet – Class 9 and 10

Chart – Number Systems

Real Numbers

  1. Rational Numbers ( Example : -9, 0 , 5/7, 2/5 etc )
  • Integers ( Example : -2 , -1 , 0 , 1 , 2 , etc )
    • Negative Integers ( Example : -2 , -1 , -3 etc )
    • Whole Numbers ( Example : 0, 1, 2, 3, 4, 5 etc )
      • Zero ( 0 )
      • Positive Integers ( Example : 2 , 3 , 4 etc )
  • Non Integral Rationals ( Example : -5/8 , 8/15 , 2 3/7 etc. )
2. Irrational Numbers ( Example : √ 5 , √ 8 , 3 √ 2 , 3 – √ 7 etc

Math Facts Uncategorized

MATHS FACTS : Addition or Subtraction of Numbers – Part 1

MATHS FACTS : Addition or Subtraction of Numbers – Part 1

Remember

1. 0 added to a number gives same number

0 + 0 = 06 + 0 = 60 + 5 = 58 + 0 = 80 + 9 = 9
0 added to a number gives same number

2. 1 added to a number gives next number

1 + 2 = 36 + 1 = 71 + 4 = 57 + 1 = 81 + 9 = 10
1 added to a number gives next number

3. 0 subtracted from a number gives same number

2 – 0 = 27 – 0 = 71 – 0 = 18 – 0 = 89 – 0 = 9
0 subtracted from a number gives same number

4. 1 subtracted from a number gives previous number

2 – 1 = 18 – 1 = 72 – 1 = 19 – 1 = 86 – 1 = 5
1 subtracted from a number gives previous number

5. Number subtracted from itself gives zero (0)

1 – 1 = 08 – 8 = 02 – 2 = 09 – 9 = 06 – 6 = 0
Number subtracted from itself gives zero (0)

You Missed

Online Quiz Quiz

Country & Capital Quiz

IEO Olympiad Preparation IEO Olympiad Preparation - Class 1 IEO Olympiad Preparation - Class 2 IEO Olympiad Preparation - Class 3 IEO Olympiad Preparation - Class 4 IEO Olympiad Preparation - Class 5 Olympiad English Class 2 SOF Olympiad SOF Olympiad - IEO SOF Olympiad Preparation

IEO Olympiad Preparation Class 1 to 5 – Singular and Plural

Olympiad IGKO Class 1 Olympiad IGKO Class 2 Olympiad IGKO Class 3 Olympiad IGKO Class 4 Olympiad IGKO Class 5 Olympiad IGKO Preparation Class 1 - 10 Olympiad Preparation - Class 1 - 10

IGKP Preparation Class 1 to Class 5 – Statue & Location Quiz

Olympiad IGKO Class 1 Olympiad IGKO Class 2 Olympiad IGKO Class 3 Olympiad IGKO Class 4 Olympiad Preparation - Class 1 - 10

IGKO Preparation Class 1 to 5 – Location