Page 103 - ArithBook5thEd ~ BCC

1 5
4. 10 ÷ 5
2 6
7 21
5. ÷
8 4
100 50
6. ÷
34 17
7. 100 ÷ 33
100
8. ÷ 5
3
Use division to answer the following questions.
1
9. How many 1 inch pieces can be cut from a board that is 36 inches long?
2
1
10. Seeds are sold in 2 -ounce packets. A gardener needs 32 ounces of seed. How many packets should
2
he buy to be sure he has enough?

3.11 Mixed Numbers and Mixed Units

Mixed numbers can be added and subtracted by first converting them into improper fractions, and very
often this is what we do. But a problem such as
1 3
75 +59
2 4
is not well-suited to this method. If we convert to improper fractions, the numerators of both fractions
would be quite large and unwieldy.

3.11.1 Vertical Addition and Subtraction

We can align mixed numbers vertically so that the fractional and whole number parts line-up, and
then separately add the fraction and whole number columns. We must ensure that the resulting mixed
number is in proper form (the fractional part must be a proper fraction), and this involves a procedure
analogous to “carrying” in whole number addition.
3
1
Example 121. Add 2 +6 .
2
4
Solution. We first align the whole number and fractional places vertically:
1
2
2
3
+ 6
4

To add the fractional parts, we write them both with their LCD, which is 4.
2
2
4
3
+ 6
4

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