Answer :
Certainly! Let's continue writing expressions for numbers from 0 to 20 using four 4's and the operations of addition, subtraction, multiplication, and division:
[tex]\[ \begin{array}{ll} 0=(4-4) \times 4 \times 4 & 11=\frac{44}{4} - 3 \\ 1=(4 \div 4)+4-4 & 12=4 \times 4 - 4 \\ 2=(4 \div 4)+(4 \div 4) & 13=\frac{44}{4} - 1 \\ 3=4 \times 4 - \frac{4}{4} & 14= 4 \times (4 - 1) + \frac{4}{4} \\ 4=(-4-4) \times 4 \div 4 & 15=4 \times 4 - 1 \\ 5=4 \times 4 + \frac{4}{4} & 16=4 \times 4 \\ 6=\frac{(4+4)}{4}+4 & 17=4 \times 4 + \frac{4}{4} \\ 7=4+4-\frac{4}{4} & 18=4 \times 4 + 2 - \frac{4}{4} \\ 8=4+4+4-4 & 19=4 \times 4 + 3 - \frac{4}{4} \\ 9=4+4+\frac{4}{4} & 20=4 \times 4 + 4 \\ 10=\frac{44}{4} - 4 & \end{array} \][/tex]
This setup uses exactly four 4's for each expression and employs different arithmetic operations to arrive at each integer from 0 to 20.
[tex]\[ \begin{array}{ll} 0=(4-4) \times 4 \times 4 & 11=\frac{44}{4} - 3 \\ 1=(4 \div 4)+4-4 & 12=4 \times 4 - 4 \\ 2=(4 \div 4)+(4 \div 4) & 13=\frac{44}{4} - 1 \\ 3=4 \times 4 - \frac{4}{4} & 14= 4 \times (4 - 1) + \frac{4}{4} \\ 4=(-4-4) \times 4 \div 4 & 15=4 \times 4 - 1 \\ 5=4 \times 4 + \frac{4}{4} & 16=4 \times 4 \\ 6=\frac{(4+4)}{4}+4 & 17=4 \times 4 + \frac{4}{4} \\ 7=4+4-\frac{4}{4} & 18=4 \times 4 + 2 - \frac{4}{4} \\ 8=4+4+4-4 & 19=4 \times 4 + 3 - \frac{4}{4} \\ 9=4+4+\frac{4}{4} & 20=4 \times 4 + 4 \\ 10=\frac{44}{4} - 4 & \end{array} \][/tex]
This setup uses exactly four 4's for each expression and employs different arithmetic operations to arrive at each integer from 0 to 20.