# Khan/khan-exercises

adding hints about M/M=1 for equivalent fractions

1 parent ac9d3cf commit f6091260c13db2397e15f259260d864bcda7f1f7 koriroys committed Oct 14, 2011
Showing with 39 additions and 2 deletions.
1. +15 −2 exercises/equivalent_fractions.html
2. +24 −0 exercises/equivalent_fractions_2.html
17 exercises/equivalent_fractions.html
 @@ -45,6 +45,12 @@

\dfrac{A}{B} = \dfrac{C}{D} and so the answer is C.

+
+

Another way to get the answer is to multiply by \dfrac{M}{M}.

+

\dfrac{M}{M} = \dfrac{1}{1} = 1 so really we are multiplying by 1.

+
+

The final equation is: \dfrac{A}{B} \times \dfrac{M}{M} = \dfrac{C}{D} so our answer is C.

+ @@ -76,11 +82,18 @@ rectchart( [C, D - C], ["#e00", "#999"] ); +

\dfrac{A}{B} = \dfrac{C}{D} and so the answer is D.

+ +
+

Another way to get the answer is to multiply by \dfrac{M}{M}.

+

\dfrac{M}{M} = \dfrac{1}{1} = 1 so really we are multiplying by 1.

+
+ +

The final equation is: \dfrac{A}{B} \times \dfrac{M}{M} = \dfrac{C}{D} so our answer is D.

-

\dfrac{A}{B} = \dfrac{C}{D} and so the answer is D.

- +
24 exercises/equivalent_fractions_2.html
 @@ -26,6 +26,12 @@

To get the right numerator C, the left numerator A is multiplied by M.

To find the right denominator, multiply the left denominator by M as well.

B \times M = D

+
+

Notice both the numerator and denominator are being multiplied by {M}.

+

We can write that as \dfrac{M}{M}, which is equal to 1 when reduced. +

So we can solve this problem by multiplying the fraction on the left by 1.

+
+

The equation becomes: \dfrac{A}{B} \times \dfrac{M}{M} = \dfrac{C}{D} so our answer is D.

@@ -37,6 +43,12 @@

To get the right denominator D, the left denominator B is multiplied by M.

To find the right numerator, multiply the left numerator by M as well.

A \times M = C

+
+

Notice both the numerator and denominator are being multiplied by {M}.

+

We can write that as \dfrac{M}{M}, which is equal to 1 when reduced. +

So we can solve this problem by multiplying the fraction on the left by 1.

+
+

The equation becomes: \dfrac{A}{B} \times \dfrac{M}{M} = \dfrac{C}{D} so our answer is C.

@@ -48,6 +60,12 @@

To get the right numerator A, the left numerator C is divided by M.

To find the right denominator, divide the left denominator by M as well.

D \div M = B

+
+

Notice both the numerator and denominator are being divided by {M}.

+

We can write that as \dfrac{M}{M}, which is equal to 1 when reduced. +

So we can solve this problem by dividing the fraction on the left by 1.

+
+

The equation becomes: \dfrac{C}{D} \div \dfrac{M}{M} = \dfrac{A}{B} so our answer is B.

@@ -59,6 +77,12 @@

To get the right denominator B, the left denominator D is divided by M.

To find the right numerator, divide the left numerator by M as well.

C \div M = A

+
+

Notice both the numerator and denominator are being divided by {M}.

+

We can write that as \dfrac{M}{M}, which is equal to 1 when reduced. +

So we can solve this problem by dividing the fraction on the left by 1.

+
+

The equation becomes: \dfrac{C}{D} \div \dfrac{M}{M} = \dfrac{A}{B} so our answer is A.