Express the following properties with variables x, y and z. (i) Commutative property of addition (ii) Commutative property of multiplication (iii) Associative property of addition (iv) Associative property of multiplication (v) Distributive property of multiplication over addition 1. Game Think of a number, multiply the number by 8, divide by 2, add 5, and then subtract 4 times the original number. 15-04-2018 No matter what number you choose the answer will always be 5. Here’s how What you say What the person Role of think Mathematics (i) Pick any number 6 (for example) n (ii) Multiply by 8 8 (6) = 48 8n (iii) Divide by 2 48 ÷ 2 = 24 8n ÷ 2 = 4n (iv) Add 5 24 + 5 = 29 4n + 5 (v) Subtract 4 times the 29 – 4 (6) = 4n + 5 – 4n = 5 original number 29 – 24 = 5 Invent your own Math magic thinking that has atleast five steps. Try it with your friend! 2. Colour the scalene triangle with Yellow, Isosceles with Green and equilateral with Red in the given adjoining figure. 15-04-2018 3. Cross Number Puzzle Rohit has to solve the given cross number puzzle to qualify for the next round of Mathematics quiz competition. Help him by evaluating the values of given expression at x = 0, y = 1, z = 2. Also help him to fill the cross number along Across and Downward with the help of given clues, (Numbers to be written in words) Across
- (a)xy + yz + zx
- (b)x2y2 + z2 – 2xyz
- (c)8 – (x+y)
- (d)x2y3 + y2z3 + z2x3 Down (e) x2 – 2xy (y–z) x3 + y 3 + z 3 (f) 3 (g) x3 + y3 + z3 – 2yz2 (h) 2x + 2y + 2z 15-04-2018
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(a) xy + yz + zx
(b) x2y2 + z2 – 2xyz
(c) 8 – (x+y)
(d) x2y3 + y2z3 + z2x3 Down (e) x2 – 2xy (y–z) x3 + y 3 + z 3 (f) 3 (g) x3 + y3 + z3 – 2yz2 (h) 2x + 2y + 2z 15-04-2018