FLC
1.5
Math 20 Arithmetic
Dividing Whole Numbers
 If multiplication is _________________________________, then division is
______________________.
 Addition and subtraction are inverse operations. They “undo” each other. Multiplication and
division are also inverse operations.
quotient
7 56
divisor dividend
Ex 1 Evaluate.
and
and
What can we conclude about the division operation?
Rewrite the above using the fraction bar.
Introduce complex fraction.
Ex 2 Change the division problem to a multiplication problem:
Address proper use of slash symbol.
.
Ex 3 Can we divide by 0? Consider
Ex 4 Divide.
a)
b)
c)
d)
e)
Note: This means
f) 3 93
g) 2 125
h) 3 1885
Check answer!!
i) 6 1415
j) 27 0
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FLC
1.5
Ex 5 How do we check division?
Ex 6 What happens when we divide by 1? By 0?
Use examples.
Divisibility Tests
A number is divisible by
 2 if it ends in 0, 2, 4, 6, or 8
 3 if the sum of the digits is divisible by 3
 4 if the last two digits make a number that is divisible by 4
 5 if it ends in 0 or 5
 6 if it is both divisible by 2 and 3
 7 has no simple test
 8 if the last three digits make a number that is divisible by 8
 9 if the sum of its digits is divisible by 9
 10 if it ends in 0
Ex 7 Which numbers are divisible by 2, 3, 5, or 10?
2
3
5
10
258
307
4216
73,000
743
374,214
205,633
8364
495
14,380
Work on in-class problems
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