Some definitions that will be useful:
  double means increase by 2 times or × 2
  triple means increase by 3 times or × 3
  quadruple means increase by 4 times or × 4

Example 1: Addition and Subtraction

Answer these word problems
Suppose you start out with 24 stamps. Michelle ends up giving you another 6 stamps. Then, because you're nice, you give George 8 stamps. How many stamps do you now have?

Translate the word problem into an equation and solve.

1. You start out with 24 stamps		24
2. Michelle gives you 6 stamps		24 + 6
3. You give George 8 stamps		24 + 6 - 8

You end up with 24 + 6 - 8 = 22 stamps.
How many stamps do you now have?

Example 2: Multiplication and Division

Answer these word problems
Suppose you start out with 10 marbles. Isabel then takes half of your marbles. At your request, Mary then decides to quadruple your quantity of marbles. Patricia then takes half of your marbles. How many marbles do you now have?

Translate the word problem into an equation and solve.

1. You start out with 10 marbles		10
2. Isabel takes half of your marbles		10 ÷ 2
3. Mary quadruples your marbles		10 ÷ 2 × 4
4. Patricia takes half of your marbles		10 ÷ 2 × 4 ÷ 2

You end up with 10 ÷ 2 × 4 ÷ 2 = 10 marbles.
How many marbles do you now have?

Example 3: Addition, Multiplication, and Division

Answer these word problems
Suppose you start out with 16 coins. At your request, Sam then decides to triple your quantity of coins. Lisa ends up giving you another 2 coins. Bob then takes half of your coins. How many coins do you now have?

Translate the word problem into an equation and solve.

1. You start out with 16 coins		16
2. Sam triples your coins		16 × 3
3. Lisa gives you 2 coins		16 × 3 + 2
4. Bob takes half of your coins		(16 × 3 + 2) ÷ 2
Remember when solving arithmetic equations, solve what's in the parantheses ( ) first.
(16 × 3 + 2) ÷ 2	=	(48 + 2) ÷ 2
	=	50 ÷ 2
	=	25

You end up with 25 coins.
How many coins do you now have?

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