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Divisibility Rules. Rules for divisibility 2 + 1 Math Rocks! - YouTube. Summary of Divisibility Rules. Divisibility by 4. Multiply 10’s digit by 2 Add this product to 1’s digit If the sum is divisible by 4 then so is the number Example: 46 9 6 9 x 2 = 18 18 + 6 = 24
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Divisibility Rules Rules for divisibility 2 + 1 Math Rocks! - YouTube
Divisibility by 4 • Multiply 10’s digit by 2 • Add this product to 1’s digit • If the sum is divisible by 4 then so is the number Example: 4696 9 x 2 = 18 18 + 6 = 24 If 24 is divisible by 4 then so is the original number
Divisibility by 8 • Multiply 100’s digit by 4 • Multiply 10’s digit by 2 • Add product of above numbers to 1’s digit • If the sum is divisible by 8 then so is the number Example: 47724 7 x 4 = 28 2 x 2 = 4 28 + 4 = 32 If 32 is divisible by 8, then so is the original number
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