Download - Mt1 Egyptian Multiplication
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EGYPTIAN MULTIPLICATION
The Ancient Egyptian used pencil and papermethod for multiplication which was based ondoubling and addition.
Unique method which they correctly viewed asrepeated addition.
Based on doubling and is also known as the
didactic method.
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Starting with one and doubling, they obtained a never-
ending sequence of numbers: 1, 2, 4, 8, 16, 32, 64,
128
These numbers are the powers of two: 20, 21, 22, 23, 24,
25, 26, 27,
Egyptians figured out is that any integer can be written
as a sum of the powers of two without repeating anyof them
For example,
14 = 8 + 4 + 223 = 16 + 4 + 2 + 1
45 = 32 + 8 + 4 + 1
160 = 128 + 32
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EGYPTIAN MULTIPLICATION OF22 x 65
Suppose we want to
multiply 22 x 65. 1 65
2 130
4 260
8 520
16 1040
Write 1 and 65,
meaning 1 lots of 65
Work down, doubling
both numbers until
the left side gets asclose as possible to,
but not larger than
22.
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1 65
2 130
4 260
8 520
16 1040
Add up the remaining
numbers on the rightto get the final
answer.
Cross out the other
rows of numbers.
Look for the numbers
on the left that addup to 22 (16+4+2).
1430
+
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EGYPTIAN MULTIPLICATIONOF 43 x 78
Suppose we want to
multiply 43 x 78. 1 78
2 156
4 312
8 624
16 1248
Write 1 and 78,
meaning 1 lots of 78
Work down, doubling
both numbers until
the left side gets asclose as possible to,
but not larger than
22.
32 2496
64 4992
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Add up the remaining
numbers on the rightto get the final
answer.
Cross out the other
rows of numbers.
Look for the numbers
on the left that addup to 43 (32+8+2+1).
1 78
2 156
4 3128 624
16 1248
32 2496
3354
+
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1 78
2 156
8 624
32 2496
3354
+
4 3
X 7 8
3 4 4
3 0 1
3 3 5 4
EGYPTIAN MULTIPLICATION
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1. If Ms. Nelly has to give 18 lectures in aweek, how many lecture she has to give in a
year?
2. An athlete jogs 26km in a day, how far willhe jog in 66 days?
3. A potter makes 45 pots in a week, how many
will he make in one and half year?
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1. If Ms. Nelly has to give 18 lectures in a week, how
many lecture she has to give in a year?
1 52
2 104
4 208
8 416
16 832
988
988 lectures in a year.
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2. An athlete jogs 26km in a day, how far will
he jog in 66 days?
1 66
2 132
4 264
8 528
16 1056
1716
1716 km in 66 days
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3. A potter makes 45 pots in a week, how many
will he make in one and half year?
1 78
2 156
4 312
8 624
16 1248
3510
One and half year = 52 weeks + (52 2) weeks= 52 weeks + 26 weeks= 78 weeks
3510 pots in one and half year.
32 2496
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