Addition, Subtraction, and Whole Numbers - Practice Problems

Background 

Let's work a couple of problems in addition and subtraction using Whole Numbers:

Question

Find 4 + 5 - 2 - 1

Find (4 + 5) - (2 - 1) 

What does 2 - 1 + 4 + 3 =  ? 

Answer

4 + 5 - 2 - 1 = 6

(4 + 5) - (2 - 1) = 8

2 - 1 + 4 + 3 =  8

Analysis 

Question 1

4 + 5 - 2 - 1

We can work this question from left to right. We first look at 4 + 5 = 9:

9 - 2 - 1

Now we look at 9 - 2 = 7:

7 - 1

And now we can find the last operation: 7 - 1 = 6

6

Question 2

(4 + 5) - (2 + 1)

Now, we know from the Order of Operations, we have to do the operations within the brackets first. We can find that 4 + 5 = 9 and 2 + 1 = 3:

9 - 3

And now we can find 9 -3 = 6

6

Question 3

2 - 1 + 4 + 3 =

We can use the equals sign to help string together several statements together that get us closer to the final answer (we'll still work left to right):

2 - 1 + 4 + 3 = 1 + 4 + 3 = 5 + 3 = 8

Vocabulary:

• Whole Numbers - the set of numbers that starts at 0 and increases by 1 (0, 1, 2, 3,...)

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Where might you have come from?

Fact-orial Index

Operations:

• Order of Operations (PEMDAS)

Operations with different kinds of numbers:

• Addition, Subtraction, and Whole Numbers

Properties:

• Commutative Property
• Associative Property

Where might we go?

Operations with different kinds of numbers:

• Multiplication, Division, and Whole Numbers
• Multiplication, Division, and Whole Numbers - Practice Problems
• Addition, Subtraction, and Integers - Practice Problems