When we write a number in expanded form, we multiply each digit by its place value. 

$\displaystyle 2$ is in the tens place, so we multiply by $\displaystyle 10$.

$\displaystyle 2\times10=20$

$\displaystyle 8$ is in the ones place, so we multiply by $\displaystyle 1$. 

$\displaystyle 8\times1=8$

$\displaystyle 2$ is in the tenths place, so we multiply by $\displaystyle \frac{1}{10}$. 

$\displaystyle 2\times\frac{1}{10}=.2$

$\displaystyle 7$ is in the hundredths place, so we multiply by $\displaystyle \frac{1}{100}$.

$\displaystyle 7\times\frac{1}{100}=.07$

$\displaystyle 8$ is in the thousandths place, so we will multiply by $\displaystyle \frac{1}{1000}$.

$\displaystyle 8\times\frac{1}{1000}=.008$

Then we add the products together. 

$\displaystyle \frac{\begin{array}[b]{r}20.000\\8.000\\ +\ .200\\ .070\\.008 \end{array}}{ \ \ \space28.278}$

When we write a number in expanded form, we multiply each digit by its place value. 

$\displaystyle 4$ is in the tens place, so we multiply by $\displaystyle 10$.

$\displaystyle 4\times10=40$

$\displaystyle 9$ is in the ones place, so we multiply by $\displaystyle 1$. 

$\displaystyle 9\times1=9$

$\displaystyle 7$ is in the tenths place, so we multiply by $\displaystyle \frac{1}{10}$. 

$\displaystyle 7\times\frac{1}{10}=.7$

$\displaystyle 5$ is in the hundredths place, so we multiply by $\displaystyle \frac{1}{100}$.

$\displaystyle 5\times\frac{1}{100}=.05$

$\displaystyle 4$ is in the thousandths place, so we will multiply by $\displaystyle \frac{1}{1000}$.

$\displaystyle 4\times\frac{1}{1000}=.004$

Then we add the products together. 

$\displaystyle \frac{\begin{array}[b]{r}40.000\\9.000\\ +\ .700\\ .050\\.004 \end{array}}{ \ \ \space49.754}$

When we write a number in expanded form, we multiply each digit by its place value. 

$\displaystyle 7$ is in the tens place, so we multiply by $\displaystyle 10$.

$\displaystyle 7\times10=70$

$\displaystyle 6$ is in the ones place, so we multiply by $\displaystyle 1$. 

$\displaystyle 6\times1=6$

$\displaystyle 1$ is in the tenths place, so we multiply by $\displaystyle \frac{1}{10}$. 

$\displaystyle 1\times\frac{1}{10}=.1$

$\displaystyle 4$ is in the hundredths place, so we multiply by $\displaystyle \frac{1}{100}$.

$\displaystyle 4\times\frac{1}{100}=.04$

$\displaystyle 8$ is in the thousandths place, so we will multiply by $\displaystyle \frac{1}{1000}$.

$\displaystyle 8\times\frac{1}{1000}=.008$

Then we add the products together. 

$\displaystyle \frac{\begin{array}[b]{r}70.000\\6.000\\ +\ .100\\ .040\\.008 \end{array}}{ \ \ \space76.148}$

In number form, two hundred fifty-three and eighty-six hundredths is $\displaystyle 253.86$. The "and" signifies the decimal, and "hundredths" signifies the place value of the last decimal number. 

In number form, seven hundred forty-two and sixty-six hundredths is $\displaystyle 742.66$. The "and" signifies the decimal, and "hundredths" signifies the place value of the last decimal number. 

In number form, three hundred twenty-four and thirty-seven hundredths is $\displaystyle 324.37$. The "and" signifies the decimal, and "hundredths" signifies the place value of the last decimal number. 

In number form, four hundred seventy-two and thirty-four hundredths is $\displaystyle 472.34$. The "and" signifies the decimal, and "hundredths" signifies the place value of the last decimal number. 

In number form, five hundred fifty-one and forty-two hundredths is $\displaystyle 551.42$. The "and" signifies the decimal, and "hundredths" signifies the place value of the last decimal number. 

In number form, six hundred ninety-seven and eighty-six hundredths is $\displaystyle 697.86$. The "and" signifies the decimal, and "hundredths" signifies the place value of the last decimal number. 

In number form, seven hundred fifty-nine and seventeen hundredths is $\displaystyle 759.17$. The "and" signifies the decimal, and "hundredths" signifies the place value of the last decimal number.