Subtract 18 from 100: Column Method Step-by-Step

Video Solution

Solution Steps

00:00 Solve

00:03 Each time consider borrowing 2 digits, and then we'll place

00:06 0 is less than 8

00:09 The tens digit is also equal to 0 so we can't borrow from it

00:13 We'll borrow one hundred from the hundreds for the tens

00:17 So now instead of 0 we'll have 10, in the tens place!

00:20 And now we'll borrow ten from the tens for the ones

00:23 Which will turn the tens from 10 to 9

00:28 So now instead of 0 we'll have 10, in the ones place!

00:32 Now subtract ones from ones, and place in ones

00:40 Subtract tens from tens, and place in tens

00:44 Place 0 in the borrowed digits

00:47 Subtract hundreds from hundreds, and place in hundreds

00:50 And that's the solution to the problem

Step-by-Step Solution

To solve the problem $100 - 18$ , we'll perform the subtraction using borrowing:

Step 1: Arrange the numbers vertically:
$\begin{aligned} & 100 \\ - & \\ & ~~18 \\ & \underline{\phantom{776}} \end{aligned}$
Step 2: Start subtracting from the rightmost digit (the units place). Subtract 8 from 0. Since 0 is smaller than 8, we need to borrow.
Step 3: Borrow from the tens place. The tens place is also 0, so we must continue to the hundreds place. Borrow 1 from the hundreds place, turning it from 1 to 0, and making the tens place 10.
Step 4: Now we have 10 in the tens place. Borrow 1 from this new tens digit, turning it from 10 to 9, and giving the units place 10.
Step 5: Subtract 8 from 10 in the units place. This gives us 2.
Step 6: Move to the tens place. Subtract 1 from 9, which gives us 8.
Step 7: As there's nothing left to subtract in the hundreds place, we are left with 0.
Step 8: Combine the results to form the final answer: 82.

Therefore, the solution to the subtraction problem is $82$ .