Solution:-
 This problem can be tackled by using distributive property of multiplication .
 This problem can be tackled by using distributive property of multiplication .
It states for any three numbers a,b and c

Similarly,
 23 × 45
23 × 45
 (21+2) ×45
(21+2) ×45
 21×45+2×45
21×45+2×45
 945 + 90
945 + 90
 1035
 1035
It can also be done as- 
 23 × 45
23 × 45
 (25-2) ×45
(25-2) ×45
 25×45-2×45
25×45-2×45
 1125-90
1125-90
 1035
 1035