Solve Vertical Addition: 81 Plus 9 Step-by-Step

Video Solution

Solution Steps

00:00 Solve

00:03 Each time calculate the sum of 2 digits, and then place

00:06 Let's start by adding ones with ones

00:09 Place the ones, add the tens to the tens

00:12 Remember 1 carry over

00:15 Place 0 where there is no digit

00:18 Add tens with tens, remember to add 1

00:21 Place the solution in tens

00:24 And this is the solution to the question

Step-by-Step Solution

The problem is to perform vertical addition for the numbers $81$ and $9$ . Here’s the step-by-step approach:

Step 1: Align the numbers vertically by their rightmost digits. The digit $1$ from $81$ is aligned with $9$ .
Step 2: Add the digits in the units place: $1 + 9 = 10$ . Here, $10$ is a two-digit result, where $0$ remains in the units place and $1$ is carried to the tens place.
Step 3: Add the digits in the tens place, including the carried digit: $8 + 1 = 9$ . This accounts for the $1$ we carried over from the units place addition.

Since no further carrying is necessary, the result of adding $81$ and $9$ is $90$ .

Therefore, the solution to the problem is $90$ , which corresponds to choice 2.