Question

Add the following by arranging in proper order. 

(i) 85 + 186 + 15 

(ii) 175 + 96 + 25 

(iii) 65 + 75 + 35 

(iv) 55 + 86 + 45

Answer 1

Add under associativity – 

(i) 85 + 186 + 15 

(85 + 186) + 15 = 85 + (186 + 15) 

271 + 15 = 85 + 201 ⇒ 286 = 286 

(ii) 175 + 96 + 25 

(175 + 96) + 25 = 175 + (96 + 25) 

271 + 25 = 175 + 121 ⇒ 296 = 296 

(iii) 65 + 75 + 35 

(65 + 75) + 35 = 65 + (75 + 35) 

140 + 35 = 65 + 110 ⇒ 175 = 175 

(iv) 55 + 86 + 45 

(55 + 86) + 45 = 55 + (86 + 45) 

141 + 45 = 55 + 131 ⇒ 186 = 186