Solve 406 minus 78: Vertical Subtraction Practice Problem

Video Solution

Solution Steps

00:04 Let's solve this problem together.

00:07 First, we'll subtract two digits at a time.

00:10 Notice that 6 is less than 8.

00:13 The tens digit is zero, so we can't borrow from it.

00:17 We'll borrow a hundred from the hundreds column for the tens.

00:21 Now, instead of zero, we have ten in the tens place.

00:25 We'll borrow ten from the tens column for the ones.

00:30 Now, the tens become nine instead of ten.

00:34 Instead of six, we now have sixteen in the ones place.

00:38 Subtract ones from ones. Place the answer in the ones column.

00:43 Subtract tens from tens. Place the result in the tens column.

00:49 Place zero in any missing digits.

00:52 Subtract hundreds from hundreds. Place the answer in the hundreds column.

00:57 And that's how we solve the problem. Well done!

Step-by-Step Solution

To solve this subtraction problem $406 - 78$ , we use the vertical subtraction method, aligning the numbers by their place values:

Step-by-step process:

Align the numbers columnwise:
406
- 78
- - - - -
Subtract each column, starting from the right:
- Units place: $6 - 8$ cannot be done directly, so we need to borrow.
- Look to the tens column (0), but it is not possible to borrow directly from zero. Instead, we move to the hundreds column.
- From the hundreds, the 4 becomes a 3 (after borrowing), and the tens place (0) becomes 10. Borrow from 10 in tens, so it becomes 9 while units becomes 16.
Perform the subtraction with borrowing adjusted:
- Units place: $16 - 8 = 8$
- Tens place: $9 - 7 = 2$
- Hundreds place: $3 - 0 = 3$

The result of subtracting 78 from 406 is $\mathbf{328}$ .

The correct answer, matching our calculation, is option 3: 328.