368
92
+23
-----
486
I tried to move it some spaces over, but seem to got mixed with the problem
The following is a method for multiplying 21x23 that relies on repeatedly doubling numbers (by adding them to themselves):
23
+23
----- 21=16+4+1
46 2
+46
-----
92 4
+92 368
----- 92
184 8 + 23
184 --------
----- 483
386 16
The answer, 483 to the multiplication problem 21*23, is shown on the bottom of the column on the right
Notice that, to use this repeated doubling method, you have to be able to only add; you don't need to know how to multiply.
A. Discuss and explain the method of repeated doubling. Address the following questions in your discussion:
I.What is the significance of the column of the numbers 2,4,8,16?
II.What is the significance of writing 21=16+4+1
III.How are the numbers 368, 92, and 23 chosen for the column on the right. Why do we add those numbers?
B.Use the method of repeated doubling to calculate 26*35. Show your work.
C.Use the method of repeated doubling to calculate 37*51. Show your work.