It is interesting and fun to try different strategies to find the easiest method.Test yourself
Try these for yourself:
a) 92 × 147 =
b) 88 × 172 =
c) 94 × 68 =
d) 96 × 372 =
The answers are:
a) 13,524
b) 15,136
c) 6,392
d) 35,712
How did you go? I used 100 × 1½ for a), 100 × 1¾ for b), 100 × 0.7 for c) and 100 × 3¾ for d).
By now you must find these calculations very easy. Experiment for yourself. Make up your own
problems. Try to solve them without writing anything down. Check your answers by casting out the
nines.
What you are doing is truly amazing. You are certainly developing exceptional skills. Keep playing
with the methods and you will find it easier with practice to do everything in your head. You are
developing great mental and mathematical skills.