Originally Posted by

**wanttolearn** Question:

One half of the birds at a pet store are yellow. Tara buys one of the yellow birds. Then one third of the birds at the store are yellow. How many yellow birds were at the pet store before Tara bought one? Explain how you know.

Answer: (Me trying, hope it is right)

Let t be the total number of birds.

Number of yellow birds, y = t/2

Now, Tara bought one.

Number of yellow birds now = y-1=(t/2)-1

which is also equals to t/3.

So, (t/2)-1 = t/3 -------equation 1

To solve this equation, bring all t's to one side of = sign.

(t/2)-(t/3)=1

(3t-2t)/6=1

3t-2t=1*6=6

t=6

If we had total 6 birds before, and half of it was yellow birds, we had 3 yellow birds before Tara bought one.

Now, my question is, how would I explain steps after equation 1 to a third grader who knows fractions but not learned subtracting fractions yet. Thanks in advance.