If its $100 dollars for the material for 30 toys, we can divide 100 by 30 to see what it would cost for each, which we can then subtract from the cost ($10) to get the profit made from each toy.
100 / 30 = 3 and 1/3 (lets round it to 3 dollars and 33 cents.)
If Heidi is selling each for $10, we can subtract 3.33 from the price to get the actual profit Heidi is making.
