1sst dady = 1.30 kg
2nd day = 0.51 kg
Question 2.
How much more did urchin eat the 1st day (compared to 2nd day).
That amount, let it be x, so we can write:
1.30 - 0.51 = a
We subtract smaller amount (2nd day) from larger amount (1sst day).
The answer would be = 0.79 kgs