0= black bear 400lbs
0 0 =polar bear 1200 lbs
0= grizzly bear 800lbs 0
If you create a visual representation the problem becomes a lot more clear.
Each one of the 0 represents 400lbs.
So the grizzly needs 2 0's to equate to the grizzly's 800lbs weight.
So the Grizzly weighs twice as much as the Black Bear
Same for the polar bear: 3 0's would create the polar bear's weight
so the polar bear weighs 3 times more than the Black Bear.
so the grizzly weighs twice as much as the black bear.
so the polar bear weighs three times as much the black bear
A good hint for word problems is to draw the problem out.