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This resource teaches students about the expanded form of numbers, such as 729 = 7 x 100 + 2 x 10 + 9, alongside the concepts of filling in blanks to complete number expressions. It emphasizes the rules of divisibility for numbers by 2, 3, 5, 9, and 10, providing shortcuts to identify if a number can be evenly divided. Additionally, it introduces the concept of representing digits with letters, enhancing understanding of number composition and arithmetic properties in a fun and engaging way.
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Standard VIII Mathematics
General form or Expanded form of 729 = 7 x 100 + 2 x10 + 9 Playing with Numbers Fill in the blanks 2 --- 54 = _x 1000 + 9 x ___+ 5 x __+ 4 92_7 = _x 1000 + _ x ___+ 3 x __+ __ 12_5 = _x 1000 + _ x ___+ 0 x __+ 5
Using letters for digits • We can write numbers where a digit is replaced by an alphabet/ letter. • Each letter represents only one digit. • 375 = 3p5 then p = 7.
Test of divisibility Tests of divisibility of any number by 2, 3, 5, 9, 10
What is Divisibility? Divisibility means that after dividing, there will beNOremainder. factors
Can you tell by just looking at this number if it is divisible by 2? by 5? by 10? by 3 ? by 9? By 6? By 4? The divisibility rules can help YOU !!! 356,821
The divisibility rules help you learn shortcuts to tell when a number can be divided by another number with no remainder. • The divisibility rules
A number is divisible by 2 if the number ends with 0,2,4,6,or8 18 ÷ 2 = 9 22 ÷ 2 = 11 (Notice that both of these numbers are even.) 21 ÷ 2 = 10 R1 (Not an even number.) Divisibility by 2
Are these numbers divisibleby 2? 127 (Not an evennumber) 937 (Not an evennumber) 4678
Divisibility by 5 A number is divisible by 5 if it ends in 0 or5. 25 ÷ 5 = 5 70 ÷ 5 = 14 23 ÷ 5 = 4 R=3
A number is divisible by 10 if its unit digit is 0. Divisibility by 10
Divisibility By:
Divisibility by 3 A number is divisible by 3 if the sum of the digits of number is divisible by 3. Is the number 135 divisible by 3? Add the digits: 1 + 3 + 5 = 9 Yes, 135 is divisible by 3 because the sum of the digits is divisible by 3.
A number is divisible by 9 if the sum of its digits is divisible by 9. 369 is divisible by 9 because 3 + 6 + 9 =18 1 + 8 = 9 AND 9 is divisible by 9 Divisibility by 9