Sabrina gave 10 cookies to her brother. Her mother gave Sabrina half the number of cookies she gave her brother. Then Sabrina gave two-thirds of her cookies to her sister. If Sabrina had 20 cookies at the start, how many cookies are left with her?
Sabrina had 20 - 10 = 
<gadget id="calculator">20-10</gadget>
<output>10</output>
10 cookies left after giving 10 cookies to her brother.
Sabrina's mother gave her 10/2 = 
<gadget id="calculator">10/2</gadget>
<output>5</output>
5 cookies.
So, she had 10 + 5 = 
<gadget id="calculator">10+5</gadget>
<output>15</output>
15 cookies then.
She gave 15 x 2/3 = 
<gadget id="calculator">15*2/3</gadget>
<output>10</output>
10 cookies to her sister.
Therefore, she only has 15 - 10 = 
<gadget id="calculator">15-10</gadget>
<output>5</output>
5 cookies left.

<result>5</result>