(i) 102 x 106
(100 + 2) (100 + 6)
= 100 (100 + 6) + 2 (100 + 6)
= 10000 + 600 + 200 + 12
= 10812
(ii) 109 x 107
This can be written as:
(100 + 9) (100 + 7)
= 100 (100 + 7) + 9 (100 + 7)
= 10000 + 700 + 900 + 63
= 11663
(iii) 35 x 37
This can be written as:
(30 + 5) (30 + 7)
= 30 (30 + 7) + 5 (30 + 7)
= 900 + 210 + 150 + 35
= 1295
(iv) 53 x 55
This can be written as:
(50 + 3) (50 + 5)
= 50 (50 + 5) + 3 (50 + 5)
= 2500 + 250 + 150 + 15
= 2915
(v) 103 x 96
This can be written as:
(100 + 3) (100 - 4)
= 100 (100 - 4) + 3 (100 - 4)
= 10000 - 400 + 300 - 12
= 10000 – 112
= 9888
(vi) 34 x 36
This can be written as:
(30 + 4) (30 + 6)
= 30 (30 + 6) + 4 (30 + 6)
= 900 + 180 + 120 + 24
= 1224
(vii) 994 x 1006
This can be written as:
(1000 - 6) (1000 + 6)
= 1000 (1000 + 6) - 6 (1000 + 6)
= 1000000 + 6000 - 6000 - 36
= 999964
