## The numbers addition to perform:

85 + 56 + 67 + 81 + 61 + 66

#### Method used below: column adding, from right to left (traditional).

### Stack the numbers on top of each other.

#### The ones digits line up in the first column from the right.

#### The tens digits line up in the next column to the left.

## Add column by column; start from the column on the right.

### Add the digits in the ones column:

#### 5 + 6 + 7 + 1 + 1 + 6 = 26

#### How did we add the digits? Explanation below.

#### Group the ones together in order to make tens:

#### 5 + 6 + 7 + 1 + 1 + 6 =

#### 5 + 6 + 7 + 1 + 1 + 6 =

#### (5 + 1 + 1) + 6 + 7 + 6 =

#### 7 + 6 + 7 + 6 =

#### 7 + 6 + 7 + 6 =

#### 7 + 3 + 3 + 7 + 6 =

#### 7 + 3 + 3 + 7 + 6 =

#### 10 + 10 + 6 =

#### 10 + 10 + 6 =

#### 20 + 6 =

#### 26

#### Change the order in which the numbers are added, the sum stays the same.

Break some number(s) into component parts, the sum stays the same.

#### The sum is a two-digit number: 26.

#### 6 is the ones digit.

Write it down at the base of the ones column.

#### 2 is the tens digit.

Carry it over to the tens column.

Write the digit above that column.

Add it with the rest of the digits in that column.

### Add the digits in the tens column:

#### 8 + 5 + 6 + 8 + 6 + 6 + 2 = 41

#### How did we add the digits? Explanation below.

#### Group the ones together in order to make tens:

#### 8 + 5 + 6 + 8 + 6 + 6 + 2 =

#### 8 + 5 + 6 + 8 + 6 + 6 + 2 =

#### (8 + 2) + 5 + 6 + 8 + 6 + 6 =

#### 10 + 5 + 6 + 8 + 6 + 6 =

#### 10 + 5 + 6 + 8 + 6 + 6 =

#### 10 + 4 + 1 + 4 + 2 + 8 + 6 + 6 =

#### 10 + 4 + 1 + 4 + 2 + 8 + 6 + 6 =

#### 10 + (4 + 6) + 1 + (4 + 6) + (2 + 8) =

#### 10 + 10 + 1 + 10 + 10 =

#### 10 + 10 + 1 + 10 + 10 =

#### (10 + 10 + 10 + 10) + 1 =

#### 40 + 1 =

#### 41

#### The sum is a two-digit number: 41.

#### 1 is the tens digit.

Write it down at the base of the tens column.

#### 4 is the hundreds digit.

Write it down at the base, next to the tens digit.

## Answer: