Question

Some problems to do in head.

(i) (130 − 47) + 17

(ii)

(iii) (298 − 4.75) + 3.75

Answer 1

(i) (130 − 47) + 17

= 130 − (47 − 17) {Using (x − y) + z = x − (y − z)}

= 130 − 30

= 100

(ii)

(iii) (298 − 4.75) + 3.75

= 298 − (4.75 − 3.75) {Using (x − y) + z = x − (y − z)}

= 298 − 1

= 297