Adding whole numbers

Adding whole numbers means that we are combining numbers to form a total.

Each number being added is called an addend and the total, which is the answer to the addition problem is called sum.

addend-image

Adding numbers with 1 digit is pretty straightforward. In general, you can do it mentally or use your fingers. Adding zero to a number never changes the number

Take a close look at the following addition problems.

The answer for one of them is wrong. Can you tell which one?

You got it right! It is the first one. 4 + 6 is not equal to 11.

4 + 6 = 10.

Now, let us move on to something more interesting, adding numbers with two digits.

When adding two-digit numbers, add the ones first. Then, add the tens.

Let us try to add 36 to 17 using expanded notation

36 = 30 + 6 and 17 = 10 + 7

adding the ones ( 6 and 7) gives 13 and 13 = 10 + 3

Adding the tens (30, 10, and 10) gives 50 and 50 + 3 = 53

Let us add 58 to 46

58 = 50 + 8 and 46 = 40 + 6

Adding the ones (8 and 6 ) gives 14 and 14 = 10 + 4

Adding the tens (50, 40, and ,10) gives 100 and 100 + 4 = 104

We can accomplish the same by arranging the numbers in vertical columns as shown below

In the above, we add the ones column first. Then, we carry over the tens to the tens column. The 1 that we carry over has a place value of 10. However, there is no need to write 10 because as we saw before in place value putting a 1 here in the tens place means that there is 1 ten.

Use the addition calculator below to practice