Complete the Addition Statement Up to 5

An addition statement is a number sentence like \( 3 + 2 = 5 \). It has three parts: the first part, the second part, and the total. Sometimes one of these numbers is missing, and it is shown as a blank box or a question mark, like \( 3 + ? = 5 \). Completing the addition statement means figuring out what number belongs in that missing spot.

This skill builds on knowing how to add numbers together. If you already feel comfortable with adding with digits up to 5, completing a statement is just working the same idea backward: instead of finding the total, you are finding one of the parts.

The easiest way to complete an addition statement is to look at a picture or use small objects like counters, buttons, or fingers. Count the objects that are already shown, then keep counting until you reach the total. The extra amount you counted is the missing number.

For example, look at this picture. There are 2 shaded circles, an empty box for the missing part, and the total should be 5 circles altogether.

Since 2 circles are already shown and the total needs to be 5, you count on from 2: "3, 4, 5" — that is 3 more counts. So the missing number is 3, and the completed statement is \( 2 + 3 = 5 \).

Follow these steps whenever a number is missing from a statement:

1. Look at the two numbers or groups you already know (the first part and the total, or the total and one part).

2. Count out objects, fingers, or dots for the part you can see.

3. Keep counting up until you reach the total number.

4. The number of extra counts is the missing number. Write it in the blank to complete the statement.

For instance, in \( 4 + ? = 5 \), you already have 4. Counting up just one more gets you to 5, so the missing number is 1: \( 4 + 1 = 5 \).

Complete this addition statement: \( 1 + ? = 4 \).

Start with 1 counter. Add more counters one at a time while counting out loud: "2, 3, 4." You added 3 more counters to get from 1 to 4, so the missing number is 3. The completed statement is \( 1 + 3 = 4 \).

You can always check your work by counting every object together from the start. If the first part and the missing part together match the total, the statement is complete and correct.

Completing addition statements helps you understand that addition can be worked in more than one direction, not just from parts to a total. This is closely connected to writing an addition statement up to 5 and to finding the correct addition statement, since both skills depend on understanding how the parts and the total of a number sentence fit together. Practicing with small, familiar numbers up to 5 makes these ideas easy to picture before moving on to larger totals.

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• Kindergarten