Ex.1 35 x 45 =____ Ex.2 75 x 85 =____ Ex.3 15 x 25 =____
Add one to the highest tens digit, and multiply this times the lower tens digit. This yields the first two digits in the answer. In Ex.1, add 1 to 4 for (1 + 4 = 5). Then 5 x 3 = 15. In Ex.2, add 8 + 1 = 9 and then 9 x 7 = 63.
Ex.1 35 x 45 = 15___ Ex.2 75 x 85 = 63___ Ex.3 15 x 25 =3___
The last digits of the answer is always 75.
Ex.1 35 x 45 = 1575 Ex.2 75 x 85 = 6375 Ex.3 14 x 25 = 375