# Khan/khan-exercises

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 Equivalent fractions
randFromArray([2, 3, 10]) randRange(1, 3) M === 10 ? 10 : randRange(2, 4) A * M B * M randVar()

What number could replace SYMBOL below?

\dfrac{A}{B} = \dfrac{SYMBOL}{D}

C

The fraction on the left represents A out of B slices of a rectangular pizza( 1 ).

init({ range: [ [0, 1], [0, 1] ], scale: [475, 25] }); rectchart( [A, B - A], [RED, GRAY] );

What if we cut the pizza( 1 ) into D slices instead? How many slices would result in the same amount of pizza( 1 )?

init({ range: [ [0, 1], [0, 1] ], scale: [475, 25] }); rectchart( [0, D], [RED, GRAY] );

We would need C slices.

init({ range: [ [0, 1], [0, 1] ], scale: [475, 25] }); rectchart( [C, D - C], [RED, GRAY] );

\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.

What number could replace SYMBOL below?

\dfrac{A}{B} = \dfrac{C}{SYMBOL}

D

The fraction on the left represents A out of B slices of a rectangular pizza( 1 ).

init({ range: [ [0, 1], [0, 1] ], scale: [475, 25] }); rectchart( [A, B - A], [RED, GRAY] );

How many total slices would we need if we want the same amount of pizza( 1 ) in C slices?

init({ range: [ [0, 1], [0, 1] ], scale: [475, 25] }); rectchart( [C, D - C], [RED, GRAY] );

We would need to cut the pizza( 1 ) into D slices.

init({ range: [ [0, 1], [0, 1] ], scale: [475, 25] }); rectchart( [C, D - C], [RED, GRAY] );

\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.