MultiplicationLives
•Cuneiform tablet found in West Asia about 2700 BC
•The table helps people figure out the area of a region by multiplying width by length.
•The first column is the width, the second is the length, and the third column is the area.
•It uses a system for writing down large numbers in base 60 (the way our clocks work today).
Let’s analyze what’s happening.
Simplest type problem:
2 x 3= 6
4 x 5= 20
What about a problem like this?
13 x 4The intersection of 13 lines 4 lines.
10 lines
10 points
4
12+
= 52
Sample Problem: 12 x 234
12 x 234102
101
101
100
100
(1 x 3)102
(1 x 2)103
(2 x 2)102
(1 x 4)101
(2 x 3)101
(2 x 4)100
2 710 8
2808
a b c x d e f
a
c
d
e
f
104
102
103
101
102
100
b
102
101
102
100
100
101
103
102
101
a2 b
1 c
0 x d
2 e
1 f
0
101 100102103104
a2d
2a
2e
1+b
1d
2a
2f0+b
1e
1+c
0d
2b
1f0+c
0e
1c
0f0
a b cd e fx
101 100102103104
a2d
2a
2e
1+b
1d
2a
2f0+b
1e
1+c
0d
2b
1f0+c
0e
1c
0f0
fcfbfaeceb
dceadbda+
cfbfafcebe
cdaebdad
a.bc x de.f
a
c
d
e
f
b
10?
10?
10?
10?
10?
10?
a.bc x de.f
a
c
d
e
f
b
101
100
100
10-1
10-2
10-1
Decimal Multiplication
€
2.1× 3.27 = 21×1
10
⎛
⎝ ⎜
⎞
⎠ ⎟× 327 ×
1
100
⎛
⎝ ⎜
⎞
⎠ ⎟
€
= 21× 327( ) ×1
10×
1
100
⎛
⎝ ⎜
⎞
⎠ ⎟
€
= 6867( ) ×1
1000
⎛
⎝ ⎜
⎞
⎠ ⎟
€
=6.867
