Adding and Subtracting Decimals with Money

Adding Decimals

by Dylan Rutherford

You may be wondering,​"How do we add decimals and why do I care about adding decimals?"

​Well, after todays' lesson you will have answers to both of those brilliant questions!

​

One of the most common for of using decimals is money, and everybody loves money

​

​Today we will discuss a few quick tips that will help you understand adding decimals together ;)

​

Multiple Choice

If a candy bar is $3.25 and you give the person at the register $5.00, how much money should she give you back?

• $1.75

• $2.25

• $1.00

• $0.50

​Lining up decimals

​The first in adding decimals is lining your numbers up just like you would with whole numbers. Ex.

5 = 5.0

+ +

​ 5 = 5.0

​ --- ---

​ 10 =10.0

​

​The beauty of zero

​When adding decimals, it is helpful to use zeros as place holder to help line up your decimals and not mix up your numbers by keeping them in their correct column.

​The zeros don't hold any value but do serve as a tool to help you get the correct answer.

​ Ex.

5.2341 5.2341

+ + ​

​3.49 3.4900

= =

8.7241​

Multiple Choice

If Jim usually has 14.92 gigs of data per per month but has been a good student and is given 2.5 more gigs of data per month, how much gigs of data does JIm have each month?

• 16.42 gigs per month

• 17.42 gigs per month

• 11.43 gigs per month

• 15.98 gigs of data

Multiple Choice

What is 3275.08571 + 5487.459?

• 7,826.0987

• 9,561.7865

• 8,762.54471

• 8,095.248

​How did we get our answer?

​ 3275.08571 3275.08571

+

​ 5487.459 5487.45900

​ =

​8,762.54471