6th Grade Math Textbook, Progress

Update your skills. See page 5.

Addition of Whole Numbers and Decimals

1-7

Mr. Kopald’s class researched electric

power usage in kilowatts. Three students

collected the data in the table. Each

calculated the total number of kilowatts

used by the three appliances in a

different way.

Study their computations below and decide

which student has the correct answer.

Charles Anetta Liz

1 1 1 1 1


1.4 5 0 6 7 
 1.4 5 0 6 7 
1.4 5 067


0. 4 .0 0 3 2 8 
4.0 0 0 0 0


 0 .0 0 3 2 8 
.1 7 4 
0.0 0 3 2 8


1.8 5 3 9 5 
 1.4 8 3 5 1 
5.4 5 3 9 5

Answer: 1.85395 kW Answer: 1.48351 kW Answer: 5.45395 kW

Liz has the correct answer because she remembered to:

 Align decimal points in the addends,

one underneath the other.

 Place the decimal point in a whole number

to the right of the ones place and write zeros

as placeholders as needed.

Study these examples.

Add: 53,301,089
1,962,752 Add: 5.0953
3.0107

Electric Power Usage

Appliance Kilowatts (kW)

Microwave oven 1.45067

Clothes dryer 4

Clock 0.00328

1 1 1

53,301,089


 1,962,752

55,263,841

1 1

5.0953


3.0107

8.106 You may drop the final zero.

2.0

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