Ex.1 41 x 5 1 =____ Ex.2 21 x 5 1 =____ Ex.3 81 x 91 =____
Multiply the tens digits for the first digits in the answer.
Ex.1 41 x 51 = 20__ Ex.2 21 x 51 = 10__ Ex.3 81 x 91 = 72__
Add the tens digits for the tens digits of the answer. *There may be a carry figure, never more than one.
Ex.1 41 x 51 = 209_ Ex.2 21 x 51 =107_ *Ex.3 81 x91 = 737_
1 is the ones digit of the answer.
Ex.1 41 x 51 = 2091 Ex.2 21 x 51 = 1071 Ex.3 81 x 91 = 7371
Try these: a) 31 x 81 = b) 51 x 61 = c) 71 x 91 =