# Lesson: Estimation Techniques: Computations \$1,000

Tara Smith E.l. Haynes Pcs Washington, DC
653 Views
12 Downloads
0 Favorites

### Lesson Objective

SWBAT use estimation techniques to solve whole number computations of amounts no greater than \$1,000

### Lesson Plan

Materials Needed: DN worksheet, dry erase markers, white board, blank paper, pencils, IND practice

……….
Do Now (3 -5 min): Teacher gives each student a DN worksheet and asks them to complete the work as quickly and quietly as possible.

Opening (2 -3 min): Teacher quickly reviews answers to the Do Now and then says, “We have learned that we can use rounding and regrouping to estimate approximate answers. By the end of this lesson, you will be able to use estimation or rounding to solve whole number computations of money amounts up to 3 digits.”

Direct Instruction (10 min): Teacher begins “Ok! Let’s quickly review front end rounding and regrouping! The two steps to front end rounding are on the board.” Teacher should write the following on the board.

1) Add the digits of the two highest place values
2) Insert zeros for the other place values

The teacher continues, “We can now begin adding and subtracting our 3 digit amounts of money for today. Let me show you how I want you to work on these problems today. Watch as I do this one on the board. ” Teacher writes the following on the board:

\$991 + \$561 =
Which Strategy?: Rounding
1,000 + 600 = 1,600

Teacher says, “Ok, why do you think I picked rounding as my strategy? I picked it because it was the fastest option. If I regrouped I would have had to do more mental math, so I went with the easiest option to get the estimate or approximate answer. I am going to complete one more problem, as you watch and then we will try some together.” Teacher writes the following on the board and explains the thought process out loud as he/she writes:

\$925 – \$531 =
Which Strategy?  Rounding
900 – 500 = 400

"Again, rounding was the faster strategy. My challenge to you during group work is to not spend more than 10 seconds on each problem. You will be completing problems almost identical to the ones I completed on the board. I want you to specify which strategy you used to get your estimate or approximate answer. Let’s get started.”

Guided Practice (8-10 min): Teacher says, “Now, I will give you five problems to do together in groups of 2 or 3 on your own paper. Help each other as you work, because in a minute I will have you do some problems on your own. Let’s get started.” Teacher writes the following on the board and gives each student time to solve the problems together in small groups.

1. \$891 + \$237 =
Which Strategy?: _____________________
Solve:__________________________________

2. \$902 – \$789 =
Which Strategy?: _____________________
Solve:__________________________________

3. \$371 – \$281 =
Which Strategy?: _____________________
Solve:__________________________________

4. \$348– \$331 =
Which Strategy?: _____________________
Solve:__________________________________

5. \$942 + \$821 =
Which Strategy?: _____________________
Solve:__________________________________

Independent Practice (5 -8 min): The teacher reviews the answers to the Guided Practice with the class and then passes out the IND practice worksheet.

Closing (2-3 min): Teacher calls the attention of the students back toward the front of the class to quickly review the answers to the Independent Practice/ ask what we learned about.

### Lesson Resources

 IND lesson 8   Classwork 201 DN lesson 8 estimation   Starter / Do Now 163
Something went wrong. See details for more info
 Nothing to upload details close