First, we line up our numbers (ones over ones, tens over tens, and hundreds over hundreds):

\[ \begin{array}{cccccccc} & \!\!\!\! 2 \!\!\!\! & \!\!\!\! 6 \!\!\!\! & \!\!\!\! 3 \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 1 \!\!\!\! & \!\!\!\! 3 \!\!\!\!& \!\!\!\! 0 \!\!\!\! \\ \hline & & & & \end{array} \]

Next, we proceed by subtracting the numbers in each place value (from right to left):

Step 1. Subtracting the ones, ${\color{blue}3} - {\color{blue}0} = {\color{blue}3}{:}$

\[ \begin{array}{cccccccc} & \!\!\!\! 2 \!\!\!\! & \!\!\!\! 6 \!\!\!\!& \!\!\!\! {\color{blue}3} \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 1 \!\!\!\! & \!\!\!\! 3 \!\!\!\!& \!\!\!\! {\color{blue}0} \!\!\!\! \\ \hline & & \!\!\!\! \!\!\!\!& \!\!\!\! {\color{blue}3} \!\!\!\! \end{array} \]

Step 2. Subtracting the tens, ${\color{blue}6} - {\color{blue}3} = {\color{blue}3}{:}$

\[ \begin{array}{cccccccc} & \!\!\!\! 2 \!\!\!\! & \!\!\!\! {\color{blue}6} \!\!\!\!& \!\!\!\! 3 \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 1 \!\!\!\! & \!\!\!\! {\color{blue}3} \!\!\!\!& \!\!\!\! 0 \!\!\!\! \\ \hline & & \!\!\!\! {\color{blue}3} \!\!\!\!& \!\!\!\! 3 \!\!\!\! \end{array} \]

Step 3. Subtracting the hundreds ${\color{blue}2} - {\color{blue}1} = {\color{blue}1}{:}$

\[ \begin{array}{cccccccc} & \!\!\!\! {\color{blue}2} \!\!\!\! & \!\!\!\! 6 \!\!\!\!& \!\!\!\! 3 \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! {\color{blue}1} \!\!\!\! & \!\!\!\! 3 \!\!\!\!& \!\!\!\! 0 \!\!\!\! \\ \hline & \!\!\!\! {\color{blue}1} \!\!\!\! & \!\!\!\! 3 \!\!\!\! & \!\!\!\! 3 \!\!\!\! \end{array} \]

Therefore, $263 - 130 = 133.$

To find how many dollars Molly has now, we need to calculate the value of \[ 657 - 112. \]

First, we line up our numbers (ones over ones, tens over tens, and hundreds over hundreds): \[ \begin{array}{cccccccc} & \!\!\!\! 6 \!\!\!\! & \!\!\!\! 5 \!\!\!\! & \!\!\!\! 7 \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 1 \!\!\!\! & \!\!\!\! 1 \!\!\!\!& \!\!\!\! 2 \!\!\!\! \\ \hline & & & & \end{array} \]

Next, we proceed by subtracting the numbers in each place value (from right to left):

Step 1. Subtracting the ones, ${\color{blue}7} - {\color{blue}2} = {\color{blue}5}{:}$ \[ \begin{array}{cccccccc} & \!\!\!\! 6 \!\!\!\! & \!\!\!\! 5 \!\!\!\!& \!\!\!\! {\color{blue}7} \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 1 \!\!\!\! & \!\!\!\! 1 \!\!\!\!& \!\!\!\! {\color{blue}2} \!\!\!\! \\ \hline & & \!\!\!\! \!\!\!\!& \!\!\!\! {\color{blue}5} \!\!\!\! & \end{array} \]

Step 2. Subtracting the tens, ${\color{blue}5} - {\color{blue}1} = {\color{blue}4}{:}$ \[ \begin{array}{cccccccc} & \!\!\!\! 6 \!\!\!\! & \!\!\!\! {\color{blue}5} \!\!\!\!& \!\!\!\! 7 \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 1 \!\!\!\! & \!\!\!\! {\color{blue}1} \!\!\!\!& \!\!\!\! 2 \!\!\!\! \\ \hline & & \!\!\!\! {\color{blue}4} \!\!\!\!& \!\!\!\! 5 \!\!\!\! & \end{array} \]

Step 3. Subtracting the hundreds ${\color{blue}6} - {\color{blue}1} = {\color{blue}5}{:}$ \[ \begin{array}{cccccccc} & \!\!\!\! {\color{blue}6} \!\!\!\! & \!\!\!\! 5 \!\!\!\!& \!\!\!\! 7 \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! {\color{blue}1} \!\!\!\! & \!\!\!\! 1 \!\!\!\!& \!\!\!\! 2 \!\!\!\! \\ \hline & \!\!\!\! {\color{blue}5} \!\!\!\! & \!\!\!\! 4 \!\!\!\! & \!\!\!\! 5 \!\!\!\! & \end{array} \]

Therefore, after buying the handbag, Molly has $\$ \bbox[3pt,Gainsboro]{\color{blue}545}.$

First, we line up our numbers: \[ \begin{array}{cccccccc} & \!\!\!\! 3 \!\!\!\! & \!\!\!\! 4 \!\!\!\! & \!\!\!\! 4 \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 2 \!\!\!\! & \!\!\!\! 1 \!\!\!\!& \!\!\!\! 7 \!\!\!\! \\ \hline & & & & \end{array} \]

Next, we proceed by subtracting the numbers in each place value (from right to left):

Step 1. We cannot compute $4 - 7.$ So, we borrow $1$ from the tens place: \[ \require{cancel} \begin{array}{cccccccc} &\!\!\!\! \!\!\! & \!\!\! \small{\color{red}3} \!\!\! & \!\!\! \small{\color{red}14} \!\!\!\! \\ &\!\!\!\! 3 \!\!\! & \!\!\! \cancel{4} \!\!\!& \!\!\! \cancel{4} \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 2 \!\!\! & \!\!\! 1 \!\!\!& \!\!\! 7 \!\!\!\! \\ \hline & \!\!\!\! \!\!\! & \!\!\! \!\!\! & \!\!\! \!\!\!\! & \end{array} \]

Step 2. Then, we subtract ones from ones, tens from tens, and hundreds from hundreds: \[ \begin{array}{cccccccc} &\!\!\!\! \!\!\! & \!\!\! \small{3} \!\!\! & \!\!\! \small{14} \!\!\!\! \\ &\!\!\!\! 3 \!\!\! & \!\!\! \cancel{4} \!\!\!& \!\!\! \cancel{4} \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 2 \!\!\! & \!\!\! 1 \!\!\!& \!\!\! 7 \!\!\!\! \\ \hline & \!\!\!\! 1 \!\!\! & \!\!\! 2 \!\!\! & \!\!\! 7 \!\!\!\! & \end{array} \]

Therefore, $344 - 217 = 127.$

First, we line up our numbers:

\[ \begin{array}{cccccccc} & \!\!\!\! 6 \!\!\!\! & \!\!\!\! 3 \!\!\!\! & \!\!\!\! 7 \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 5 \!\!\!\! & \!\!\!\! 5 \!\!\!\!& \!\!\!\! 5 \!\!\!\! \\ \hline & & & & \end{array} \]

Next, we proceed by subtracting the numbers in each place value (from right to left):

Step 1. Subtracting the ones, ${\color{blue}7} - {\color{blue}5} = {\color{blue}2}{:}$

\[ \begin{array}{cccccccc} &\!\!\!\! 6 \!\!\!\! & \!\!\!\! 3 \!\!\!\!& \!\!\!\! {\color{blue}7} \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 5 \!\!\!\! & \!\!\!\! 5 \!\!\!\!& \!\!\!\! {\color{blue}5} \!\!\!\! \\ \hline &\!\!\!\! \!\!\!\! & \!\!\!\! \!\!\!& \!\!\!\! {\color{blue}2} \!\!\!\! \end{array} \]

Step 2. We cannot compute $3 - 5.$ So, we borrow $1$ from the hundreds place:

\[ \require{cancel} \begin{array}{cccccccc} &\!\!\!\! \small{\color{red}5} \!\!\! & \!\!\! \small{\color{red}13} \!\!\! & \!\!\! \!\!\!\! \\ &\!\!\!\! \cancel{6} \!\!\! & \!\!\! \cancel{3} \!\!\!& \!\!\! 7 \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 5 \!\!\! & \!\!\! 5 \!\!\!& \!\!\! 5 \!\!\!\! \\ \hline & \!\!\!\! \!\!\! & \!\!\! \!\!\! & \!\!\! 2 \!\!\!\! \end{array} \]

Step 3: Then, we subtract tens and hundreds:

\[ \begin{array}{cccccccc} &\!\!\!\! \small{5} \!\!\! & \!\!\! \small{13} \!\!\! & \!\!\! \!\!\!\! \\ &\!\!\!\! \cancel{6} \!\!\! & \!\!\! \cancel{3} \!\!\!& \!\!\! 7 \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 5 \!\!\! & \!\!\! 5 \!\!\!& \!\!\! 5 \!\!\!\! \\ \hline & \!\!\!\! 0 \!\!\! & \!\!\! 8 \!\!\! & \!\!\! 2 \!\!\!\! \end{array} \]

Therefore, $637 - 555 = 82.$

First, we line up our numbers:

\[ \begin{array}{cccccccc} & \!\!\!\! 3 \!\!\!\! & \!\!\!\! 3 \!\!\!\! & \!\!\!\! 1 \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 2 \!\!\!\! & \!\!\!\! 3 \!\!\!\!& \!\!\!\! 2 \!\!\!\! \\ \hline & & & & \end{array} \]

Next, we proceed by subtracting the numbers in each place value (from right to left):

Step 1. We cannot compute $1 - 2.$ So, we borrow $1$ from the tens place. Then, subtracting the ones, ${\color{blue}11} - {\color{blue}2} = {\color{blue}9}{:}$

\[ \begin{array}{cccccccc} &\!\!\!\! \!\!\! & \!\!\! \small{2} \!\!\! & \!\!\! \small{\color{blue}11} \!\!\!\! \\ &\!\!\!\! 3 \!\!\! & \!\!\! \cancel{3} \!\!\!& \!\!\! \cancel{1} \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 2 \!\!\! & \!\!\! 3 \!\!\!& \!\!\! {\color{blue}2} \!\!\!\! \\ \hline &\!\!\!\! \!\!\! & \!\!\! \!\!\!& \!\!\! {\color{blue}9} \!\!\!\! \end{array} \]

Step 2. We cannot compute $2 - 3.$ So, we borrow $1$ from the hundreds place. Then, we subtract tens and hundreds:

\[ \begin{array}{cccccccc} &\!\!\!\! \small{2} \!\!\! & \!\!\! \small{12} \!\!\! & \!\!\! \small{11} \!\!\!\! \\ &\!\!\!\! \cancel{3} \!\!\! & \!\!\! \cancel{3} \!\!\!& \!\!\! \cancel{1} \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 2 \!\!\! & \!\!\! 3 \!\!\!& \!\!\! 2 \!\!\!\! \\ \hline & \!\!\!\! 0 \!\!\! & \!\!\! 9 \!\!\! & \!\!\! 9 \!\!\!\! \end{array} \]

Therefore, $331 - 232 = 99.$

To find how many grams of flour Luis used, we need to calculate the value of \[ 637 - 148. \]

First, we line up our numbers: \[ \begin{array}{cccccccc} & \!\!\!\! 6 \!\!\!\! & \!\!\!\! 3 \!\!\!\! & \!\!\!\! 7 \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 1 \!\!\!\! & \!\!\!\! 4 \!\!\!\!& \!\!\!\! 8 \!\!\!\! \\ \hline & & & & \end{array} \]

Next, we proceed by subtracting the numbers in each place value (from right to left):

Step 1. We cannot compute $7 - 8.$ So, we borrow $1$ from the tens place. Then, subtracting the ones, ${\color{blue}17} - {\color{blue}8} = {\color{blue}9}{:}$ \[ \begin{array}{cccccccc} &\!\!\!\! \!\!\! & \!\!\! \small{2} \!\!\! & \!\!\! \small{\color{blue}17} \!\!\!\! \\ &\!\!\!\! 6 \!\!\! & \!\!\! \cancel{3} \!\!\!& \!\!\! \cancel{7} \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 1 \!\!\! & \!\!\! 4 \!\!\!& \!\!\! {\color{blue}8} \!\!\!\! \\ \hline &\!\!\!\! \!\!\! & \!\!\! \!\!\!& \!\!\! {\color{blue}9} \!\!\!\! & \end{array} \]

Step 2. We cannot compute $2 - 4.$ So, we borrow $1$ from the hundreds place. Then, we subtract tens and hundreds: \[ \begin{array}{cccccccc} &\!\!\!\! \small{5} \!\!\! & \!\!\! \small{12} \!\!\! & \!\!\! \small{17} \!\!\!\! \\ &\!\!\!\! \cancel{6} \!\!\! & \!\!\! \cancel{3} \!\!\!& \!\!\! \cancel{7} \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 1 \!\!\! & \!\!\! 4 \!\!\!& \!\!\! 8 \!\!\!\! \\ \hline & \!\!\!\! 4 \!\!\! & \!\!\! 8 \!\!\! & \!\!\! 9 \!\!\!\! & \end{array} \]

Therefore, Luis used $\bbox[3pt,Gainsboro]{\color{blue}489}$ grams of flour.

First, we line up our numbers:

\[ \begin{array}{cccccccc} & \!\!\!\! 8 \!\!\!\! & \!\!\!\! 0 \!\!\!\! & \!\!\!\! 4 \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 4 \!\!\!\! & \!\!\!\! 5 \!\!\!\!& \!\!\!\! 9 \!\!\!\! \\ \hline & & & & \end{array} \]

Next, we proceed by subtracting the numbers in each place value (from right to left):

Step 1. We cannot compute $4 - 9,$ and there are $0$ tens to borrow from. So, we borrow $1$ from the hundreds place first:

\[ \require{cancel} \begin{array}{cccccccc} &\!\!\!\! \small{\color{red}7} \!\!\! & \!\!\! \small{\color{red}10} \!\!\! & \!\!\! \!\!\!\! \\ &\!\!\!\! \cancel{8} \!\!\! & \!\!\! \cancel{0} \!\!\!& \!\!\! 4 \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 4 \!\!\! & \!\!\! 5 \!\!\!& \!\!\! 9 \!\!\!\! \\ \hline & \!\!\!\! \!\!\! & \!\!\! \!\!\! & \!\!\! \!\!\!\! \end{array} \]

Then, we borrow $1$ from the tens place:

\[ \require{cancel} \begin{array}{cccccccc} &\!\!\!\! \!\!\! & \!\!\! \small{\color{red}9} \!\!\! & \!\!\! \small{\color{red}14} \!\!\!\! \\ &\!\!\!\! \small{7} \!\!\! & \!\!\! \cancel{\small{10}} \!\!\! & \!\!\! \cancel{\small{4}} \!\!\!\! \\ &\!\!\!\! \cancel{8} \!\!\! & \!\!\! \cancel{0} \!\!\!& \!\!\! \cancel{4} \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 4 \!\!\! & \!\!\! 5 \!\!\!& \!\!\! 9 \!\!\!\! \\ \hline & \!\!\!\! \!\!\! & \!\!\! \!\!\! & \!\!\! \!\!\!\! \end{array} \]

Step 2. Then, we subtract ones, tens, and hundreds:

\[ \require{cancel} \begin{array}{cccccccc} &\!\!\!\! \!\!\! & \!\!\! \small{\color{red}9} \!\!\! & \!\!\! \small{14} \!\!\!\! \\ &\!\!\!\! \small{7} \!\!\! & \!\!\! \cancel{\small{10}} \!\!\! & \!\!\! \cancel{\small{4}} \!\!\!\! \\ &\!\!\!\! \cancel{8} \!\!\! & \!\!\! \cancel{0} \!\!\!& \!\!\! \cancel{4} \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 4 \!\!\! & \!\!\! 5 \!\!\!& \!\!\! {9} \!\!\!\! \\ \hline & \!\!\!\! 3 \!\!\! & \!\!\! 4 \!\!\! & \!\!\! 5 \!\!\!\! \end{array} \]

Therefore, $804 - 459 = 345.$

To determine many grams of flour remain in the pack, we need to calculate the value of \[ 900 - 776. \]

First, we line up our numbers:

\[ \begin{array}{cccccccc} & \!\!\!\! 9 \!\!\!\! & \!\!\!\! 0 \!\!\!\! & \!\!\!\! 0 \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 7 \!\!\!\! & \!\!\!\! 7 \!\!\!\!& \!\!\!\! 6 \!\!\!\! \\ \hline & & & & \end{array} \]

Next, we proceed by subtracting the numbers in each place value (from right to left):

Step 1. We cannot compute $0 - 6,$ and there are $0$ tens to borrow from. So, we borrow $1$ from the hundreds place first:

\[ \require{cancel} \begin{array}{cccccccc} &\!\!\!\! \small{\color{red}8} \!\!\! & \!\!\! \small{\color{red}10} \!\!\! & \!\!\! \!\!\!\! \\ &\!\!\!\! \cancel{9} \!\!\! & \!\!\! \cancel{0} \!\!\!& \!\!\! 0 \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 7 \!\!\! & \!\!\! 7 \!\!\!& \!\!\! 6 \!\!\!\! \\ \hline & \!\!\!\! \!\!\! & \!\!\! \!\!\! & \!\!\! \!\!\!\! \end{array} \]

Then, we borrow $1$ from the tens place:

\[ \require{cancel} \begin{array}{cccccccc} &\!\!\!\! \!\!\! & \!\!\! \small{\color{red}9} \!\!\! & \!\!\! \small{\color{red}10} \!\!\!\! \\ &\!\!\!\! \small{8} \!\!\! & \!\!\! \cancel{\small{10}} \!\!\! & \!\!\! \cancel{\small{0}} \!\!\!\! \\ &\!\!\!\! \cancel{9} \!\!\! & \!\!\! \cancel{0} \!\!\!& \!\!\! \cancel{0} \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 7 \!\!\! & \!\!\! 7 \!\!\!& \!\!\! 6 \!\!\!\! \\ \hline & \!\!\!\! \!\!\! & \!\!\! \!\!\! & \!\!\! \!\!\!\! \end{array} \]

Step 2. Then, we subtract ones, tens, and hundreds:

\[ \require{cancel} \begin{array}{cccccccc} &\!\!\!\! \!\!\! & \!\!\! \small{\color{red}9} \!\!\! & \!\!\! \small{10} \!\!\!\! \\ &\!\!\!\! \small{8} \!\!\! & \!\!\! \cancel{\small{10}} \!\!\! & \!\!\! \cancel{\small{0}} \!\!\!\! \\ &\!\!\!\! \cancel{9} \!\!\! & \!\!\! \cancel{0} \!\!\!& \!\!\! \cancel{0} \!\!\!\! \\ \!\!\!\!-\!\!\!\! & \!\!\!\! 7 \!\!\! & \!\!\! 7 \!\!\!& \!\!\! 6 \!\!\!\! \\ \hline & \!\!\!\! 1 \!\!\! & \!\!\! 2 \!\!\! & \!\!\! 4 \!\!\!\! \end{array} \]

Therefore, there are $124$ grams of flour remaining.