Final answer:
To find 4/10 of 20, multiply 4/10 by 20. The fraction left is 12.
Step-by-step explanation:
To find 4/10 of 20, you multiply 4/10 by 20.
First, divide 4 by 10: 4 ÷ 10 = 0.4.
Then, multiply 0.4 by 20: 0.4 x 20 = 8.
So, 4/10 of 20 is 8.
The fraction left can be found by subtracting the value you found (8) from the original value (20): 20 - 8 = 12.
Therefore, the fraction left is 12.