Chapter 1, Problem 1IR

To determine

To add: The numbers 23, 46 and 79.

Answer to Problem 1IR

The sum of 23, 46 and 79 is 148.

Explanation of Solution

Definition used:

The process of finding the sum of the given addends is addition.

Procedure used:

First add the one’s-place digits, then go for ten’s-place digits and proceed like this. If the sum of one’s place contains both ten’s and one’s then place the one’s digits in one’s place and carry the ten’s digit to the ten’s place and obtain the sum of ten’s place digits and so on.

Calculation:

Line up the given addends according to their place values.

$\underset{\_}{\begin{array}{cccc}& & 2& 3\\ & & 4& 6\\ +& & 7& 9\end{array}}$

Add the one’s-place digits.

The numbers in the one’s place are 3, 6 and 9. So the sum is 18.

Place 8 in one’s column and carry 1 to ten’s place.

$\begin{array}{l}\underset{\_}{\begin{array}{cccc}& & \stackrel{1}{2}& 3\\ & & 4& 6\\ +& & 7& 9\end{array}}\\ \begin{array}{cccc}& & & 8\end{array}\end{array}$

The numbers in the ten’s place are 1, 2, 4 and 7. So the sum is 14.

Place 4 in the ten’s column and 1 to hundred’s column

$\begin{array}{l}\underset{\_}{\begin{array}{cccc}& & \stackrel{1}{2}& 3\\ & & 4& 6\\ +& & 7& 9\end{array}}\\ \begin{array}{cccc}& 1& 4& 8\end{array}\end{array}$

Therefore, the sum of 23, 46 and 79 is 148.