To subtract two mixed numbers, we subtract whole numbers from whole numbers and fractions from fractions.

Subtracting the whole numbers, we get $4-1 = {\color{red}{3}}.$

Now we subtract the fractions:

\[ \dfrac{5}{6} - \dfrac 2 3 \]

To subtract two fractions with unlike denominators, we must express each fraction as an equivalent fraction with a common denominator.

In this question, we can make a common denominator of $6.$

To put $\dfrac 2 3$ over a denominator of $6,$ we multiply the numerator and denominator by $2$:

\[ \dfrac{2}{3} = \dfrac{2\times 2}{3\times 2} = \dfrac{4}{6} \]

We can now subtract the fractions. We keep the denominator the same, and we subtract the numerators.

\begin{align*} \dfrac{5}{6} - \dfrac{4}{6} = \color{blue} \dfrac{1}{6} \end{align*}

Therefore,

\[ 4\,\dfrac{5}{6} - 1\,\dfrac 2 3 = {\color{red}{3}}\,{\color{blue}{\dfrac 1 6}} =3\, \dfrac 1 6. \]

To subtract two mixed numbers, we subtract whole numbers from whole numbers and fractions from fractions.

Subtracting the whole numbers, we get $5-2 = {\color{red}{3}}.$

Now we subtract the fractions:

\[ \dfrac{9}{10} - \dfrac 2 {5} \]

To subtract two fractions with unlike denominators, we must express each fraction as an equivalent fraction with a common denominator.

In this question, we can make a common denominator of $10.$

To put $\dfrac 2 5$ over a denominator of $10,$ we multiply the numerator and denominator by $2$:

\[ \dfrac{2}{5} = \dfrac{2\times 2}{5\times 2} = \dfrac{4}{10} \]

We can now subtract the fractions. We keep the denominator the same, and we subtract the numerators.

\begin{align*} \dfrac{9}{10} - \dfrac{4}{10} = \color{blue} \dfrac{5}{10} \end{align*}

Next, we reduce the fraction to its lowest terms.

\[ \dfrac{5}{10} = \dfrac{5\div 5}{10\div 5} = \color{blue} \dfrac{1}{2} \]

Therefore,

\[ 5\,\dfrac{9}{10} - 2\,\dfrac 2 {5} = {\color{red}{3}}\,{\color{blue}{\dfrac 1 2}}.\]

To subtract two mixed numbers, we subtract whole numbers from whole numbers and fractions from fractions.

Subtracting the whole numbers, we get $1-1 = {\color{red}{0}}.$

Now we subtract the fractions:

\[ \dfrac{4}{5} - \dfrac 1 {10} \]

To subtract two fractions with unlike denominators, we must express each fraction as an equivalent fraction with a common denominator.

In this question, we can make a common denominator of $10.$

To put $\dfrac 4 5$ over a denominator of $10,$ we multiply the numerator and denominator by $2$:

\[ \dfrac{4}{5} = \dfrac{4\times 2}{5\times 2} = \dfrac{8}{10} \]

We can now subtract the fractions. We keep the denominator the same, and we subtract the numerators.

\begin{align*} \dfrac{8}{10} - \dfrac{1}{10} = \color{blue} \dfrac{7}{10} \end{align*}

Therefore,

\[ 1\,\dfrac{4}{5} - 1\,\dfrac1 {10} = {\color{red}{0}}\,{\color{blue}{\dfrac 7 {10}}} = \dfrac 7 {10}. \]

So the missing number is $7.$

To subtract two mixed numbers, we subtract whole numbers from whole numbers and fractions from fractions.

Subtracting the whole numbers, we get $5-5 = {\color{red}{0}}.$

Now we subtract the fractions:

\[ \dfrac{3}{4} - \dfrac 3 8 \]

To subtract two fractions with unlike denominators, we must express each fraction as an equivalent fraction with a common denominator.

In this question, we can make a common denominator of $8.$

To put $\dfrac 3 4$ over a denominator of $8,$ we multiply the numerator and denominator by $2$:

\[ \dfrac{3}{4} = \dfrac{3\times 2}{4\times 2} = \dfrac{6}{8} \]

We can now subtract the fractions. We keep the denominator the same, and we subtract the numerators.

\begin{align*} \dfrac{6}{8} - \dfrac{3}{8} = \color{blue} \dfrac{3}{8} \end{align*}

Therefore,

\[ 5\,\dfrac{3}{4} - 5\,\dfrac 3 8= {\color{red}{0}}\,{\color{blue}{\dfrac 3 8}} = \dfrac 3 8. \]

To subtract two mixed numbers, we subtract whole numbers from whole numbers and fractions from fractions.

Subtracting the whole numbers, we get $4-1 = {\color{red}{3}}.$

Now we subtract the fractions:

\[ \dfrac{4}{5} - \dfrac 1 3 \]

To subtract the fractions, we need to find the least common multiple of the denominators ($5$ and $3$).

• Multiples of 5: $\quad 5,10,{\color{purple}{15}},\ldots$

• Multiples of 3: $\quad 3,6,9,12,{\color{purple}{15}},\ldots$

Therefore, the least common denominator of $5$ and $3$ is ${\color{purple}{15}}.$

• To put $\dfrac 4 5 $ over a denominator of $15,$ we multiply the numerator and denominator by $3$: \[ \dfrac{4}{5} = \dfrac{4\times 3}{5 \times 3 } = \dfrac{12}{15} \]

• To put $\dfrac 1 3 $ over a denominator of $15,$ we multiply the numerator and denominator by $5 $: \[ \dfrac{1}{3} = \dfrac{1\times 5 }{3 \times 5 } = \dfrac{5}{15} \]

We can now subtract the fractions. We keep the denominator the same, and we subtract the numerators:

\begin{align*} \dfrac{4}{5} - \dfrac 1 3 = \dfrac{12}{15} - \dfrac{5}{15} = \color{blue} \dfrac{7}{15} \end{align*}

Therefore:

\[ 4\,\dfrac{4}{5} - 1\,\dfrac 1 3 = 3\,\dfrac {\bbox[2px,lightgray]{7}}{15} \]

So the missing number is $7.$

To subtract two mixed numbers, we subtract whole numbers from whole numbers and fractions from fractions.

Subtracting the whole numbers, we get $3-1 = {\color{red}{2}}.$

Now we subtract the fractions:

\[ \dfrac{3}{8} - \dfrac 1 6 \]

To subtract the fractions, we need to find the least common multiple of the denominators ($8$ and $6$).

• Multiples of 8: $\quad 8,16,{\color{purple}{24}},\ldots$

• Multiples of 6: $\quad 6,12,18,{\color{purple}{24}},\ldots$

Therefore, the least common denominator of $8$ and $6$ is ${\color{purple}{24}}.$

• To put $\dfrac 3 8 $ over a denominator of $24,$ we multiply the numerator and denominator by $3$: \[ \dfrac{3}{8} = \dfrac{3\times 3}{8 \times 3 } = \dfrac{9}{24} \]

• To put $\dfrac 1 6 $ over a denominator of $24,$ we multiply the numerator and denominator by $4 $: \[ \dfrac{1}{6 } = \dfrac{1\times 4 }{6 \times 4 } = \dfrac{4}{24} \]

We can now subtract the fractions. We keep the denominator the same, and we subtract the numerators:

\begin{align*} \dfrac{3}{8} - \dfrac 1 6 = \dfrac{9}{24} - \dfrac 4 {24} = \color{blue} \dfrac{5}{24} \end{align*}

Therefore,

\[ 3\,\dfrac{3}{8} - 1\,\dfrac 1 6 = {\color{red}{2}}\,{\color{blue} \dfrac{5}{24}} \]