Estimation
Addition
Subtraction
Multi-Step
100
Name two types of estimation tools.

Rounding, front-end estimation or compatible numbers

100

What's the sum?

2,349 + 8,254

10,603

100

What's the difference?

6,971 - 817

6,154

100

Solve for x:

1,048 + 85,473 - 918 - 5 = x

85,598

200

The high school basketball team made the following shots over the past 3 years.  Which two months did they make about 4,000 shots?

This Year: 2,093

Last Year: 2,642

Two Years Ago: 1,968

This year and two years ago.
200
Error Anaylsis:


Sam got the incorrect answer of 16,577 when adding 4721 + 8856.  What mistake did they make?

They did not carry the 1 when adding 7+8 in the hundredths place.

200

Name 4 words or phrases that indicate subtraction.

less/less than

fewer/fewer than

how many/much more/taller/greater/heavier

difference

take away, deduct, decrease, withdraw, remove, spend

200

A paper company is delivering paper to three schools.  They drop off 13,900 sheets of paper to the first school.  They drop off 5,617 less sheets to the second school than the first school.  They drop off 2,096 more to the third school than the second school.  How many sheets of paper did the paper company drop off in all?

32,562 sheet of paper delivered in all

300
If someone was guessing how many total items of food were collected over 2 weeks, and 450 were collected in the first week and 612 were collected in the second week, what is a reasonable estimate for the total?

about 1000 food items collected

300

Name 4 words or phrases that indicate addition.

more/greater/taller/bigger than

increased, deposit, plus, sum, total, in all, altogether, combined

300

Error Analysis:

Henry got 24,045 when subtracting 28,709 - 4,641.  What mistake did he make?  And what should he have gotten?

Henry did not borrow from the 7 when subtracting 0-4 in the tens place.

He should have gotten 24,068.

300
A family goes on a road trip and will drive 1,042 miles total.  They drive 480 miles and then take a break.  Then they drive 312 miles and take another break.  How many miles are left to drive?

250 miles are left to drive

400

What is a reasonable estimate for 

18,830 - 9,183

19,000 - 9,000 = 10,000 

or 

20,000 - 9,000 = 11,000

400

What is the sum?

36,672 + 28,937

65,609

400

What is the difference?

10,000 - 4,382

5,618

400

Devon is collecting 500 bags of mulch for a his community garden.  He already has 360 bags.  An organization donated 80 bags.  How many bags are left for Devon to collect?

Devon has 60 more bags to collect.
500

Which estimation tool gives you an estimation closest to the real answer and why?


Rounding or Front-End Estimation

Rounding, because you can choose any place value to round to and the lower the place value you round to, the closer the the actual number you are using.

Also, the digit to the left determines whether to round up or stay the same, which allows the number to stay closer to its original value.

500

Joe threw his football 6,481cm into the air.  Aaron threw his football 3,657cm into the air.  Write an equation with a variable that represents the total centimeters both footballs were thrown.

6,481 + 3,657 = t

500

Write an equation with a variable for the following scenario:

Together, Alex and Sophia have $4,031 in monopoly.  Sophia has $2,473.  How much money does Alex have?

4031-2473 = A

500

Together, Jerry and Michael spent 327 minutes playing outside on Saturday.  Jerry had to go home after 118 minutes while Michael stayed outside.  But then he came back outside for 33 more minutes until they both had to go home.  Write an equation with a variable for the amount of time Michael stayed outside.

327 - 118 - 33 = J

M
e
n
u