Skill: Subtract multi-digit whole numbers

Line up the numbers by place value: ones under ones, tens under tens, and so on. Subtract from right to left. When a top digit is too small, regroup by trading 1 unit from the place to its left for 10 units in the current place.

Example:

$$\begin{array}{r} 52{,}004\\ - 17{,}628\\ \hline \end{array}$$

1. Ones: $4$ is less than $8$. Regroup. Since the tens and hundreds digits are $0$, take 1 thousand from the $2$ thousands. The $2$ becomes $1$. Turn the $0$ hundreds into $(10)$ hundreds, then trade 1 hundred for $(10)$ tens, and trade 1 ten for $(10)$ ones. Now there are $(14)$ ones and $9$ tens.

$$14-8=6$$

2. Tens:

$$9-2=7$$

3. Hundreds: There are $9$ hundreds left.

$$9-6=3$$

4. Thousands: $1$ is less than $7$, so regroup 1 ten thousand. The $5$ becomes $4$, and the $1$ thousand becomes $(11)$ thousands.

$$11-7=4$$

5. Ten-thousands:

$$4-1=3$$

So,

$$\begin{array}{r} 52{,}004\\ - 17{,}628\\ \hline 34{,}376 \end{array}$$

Check by addition:

$$17{,}628+34{,}376=52{,}004$$

Therefore, $(52{,}004-17{,}628=\boxed{34{,}376})$.