cross multiplying is a strategy for finding the missing part of a set of equivalent fractions
DESCRIPTION
Cross multiplying is a strategy for finding the missing part of a set of equivalent fractions. The letter a is supposed to represent the number you don’t know yet. It is called a variable. 1. 5. =. 2. a. Use that brain in your head: If 10 is 1 times some number, - PowerPoint PPT PresentationTRANSCRIPT
Cross multiplying is astrategy for finding
the missing part of aset of equivalent
fractions.12
=5a
The letter a is supposedto represent the
number you don’t know yet. It is called a
variable.
Cross multiplying is astrategy for finding
the missing part of aset of equivalent
fractions.
12
=5a
The letter a is supposedTo represent the
numberYou don’t know yet. It
is called a variable.
2 x 5 = 1 x a
10 = 1 x a
Use that brain in your head:If 10 is 1 times some number,
what is that number?
12
=5a
2 x 5 = 1 x a
10 = 1 x a
Yes. Since 10 = 1 x 10,the variable a in this
case is 10.10
37
=12a
7 x 12 = 3 x a
84 = 3 x a
If 84 is three times some number, then
84 ÷ 3 will reveal the missing amount.
37
=12a
7 x 12 = 3 x a
84 = 3 x a
If 84 is three times some number, then
84 ÷ 3 will reveal the missing amount.
8 42
362 4
8
420
37
=12a
7 x 12 = 3 x a
84 = 3 x a
If 84 is three times some number, then
84 ÷ 3 will reveal the missing amount.
8 42
362 4
8
42028
15
25__ =
b
100__
15 x 100 = 25 x b
1,500 ÷ 25 = b
1500256
0
3
(6 x 2) +3=15
150 0
0
006 0 = b
6 0
812
n100
=
800 = 12 n800 /12 = n
8 0 0126
728 0
6
728
0
0
6
7 2 n66.6 =
66.6
A LOT OF STEPS!
Soon you willknow how to solveeven harder problems!