How do you use estimation
to check the sum of 437 and
529?
In this lesson you will learn
to check if your answers to
story problems are
reasonable by using front end
estimation.
Let’s
Review
Let’s
Review
Reasonable means it makes sense.
A Common
Let’s
Review Mistake
Not completing all steps in multi-step
problems and not checking back to
see if the answer makes sense.
CoreReview
Lesson
Let’s
Front end estimation
Rounding to the lead digit
Look at the first digit
437
The 4 is in the hundred’s place so it’s
value is 400.
CoreReview
Lesson
Let’s
Prove with place value tools
437
CoreReview
Lesson
Let’s
437 using front end estimation is 400.
Rounding to the
lead digit.
CoreReview
Lesson
Let’s
Front end estimation
Rounding to lead digit
Look at the first digit
529
The 5 is in the hundred’s place so it’s
value is 500.
CoreReview
Lesson
Let’s
Prove with place value tools
529
CoreReview
Lesson
Let’s
529 using front end estimation is 500.
Rounding to the
lead digit.
CoreReview
Lesson
Let’s
1
437
+ 529
9 66
400
+500
900
CoreReview
Lesson
Let’s
Jack baked 232 cupcakes.
Jill baked 318 cupcakes.
They sold 115.
How many do they have left?
Jack 232 cupcakes.
Jill 318 cupcakes.
They sold 115.
CoreReview
Lesson
Let’s
Jack 232 cupcakes.
Jill 318 cupcakes.
They sold 115.
232 + 318 -115 = How many cupcakes are left
1
232
+ 31 8
5 50
4
550
-1 1 5
4 3 5 cupcakes are left
CoreReview
Lesson
Let’s
Jack 232 cupcakes.
200
Jill 318 cupcakes.
300
They sold 115.
100
232 + 318 -115 = 435 cupcakes are left
200 + 300 -100 = 400 cupcakes are left
In this lesson you have
learned to check if your
answers to story problems
are reasonable by using front
end estimation.
Guided
Practice
Let’s
Review
Third grade is collecting canned
goods for the food pantry. The goal
is 1000 cans. In week one 122 cans
were collected. In week two 315
cans were collected. In week three
450 cans were collected. How many
are still needed to reach the goal?
Guided
Practice
Let’s
Review
Goal is 1000 cans
Cans collected:
Week one:
122
Week two:
315
Week three: + 450
Extension
Let’s
ReviewActivities
“ Story Problem Mix-Up”
Needed: 3 players and scrap paper strips
To Play: (play 3 rounds each player leads one)
-First player gives a topic (like the can drive)
-all players write a sentence including a
number and action to go with the topic
-first player creates a story with all sentences
-each player solves, showing strategies used
-CHECK for reasonable answer using front
end estimation! Compare and discuss
Extension
Let’s
ReviewActivities
Story Problem Bank
As players finish rounds of play in Story
Problem Mix Up, record the story
problems and file so partners or individual
students can work on just solving and then
checking using front end estimation.
Extension
Let’s
ReviewActivities
Front End Estimation Roll-a- thon!
Needed: 3 players, 3 dice, paper
To Play: each player gets 1 roll per round
Choose 2 or 3 dice, before roll say add or
subtract. Keep track of each play. When
all players have gone solve the equation.
Use front end estimation to check if
answer is reasonable. Compare and
discuss.
Quick Quiz
Let’s
Jack and Jill need to bring 500 pails
Review
up the hill. Jack carried 224. Jill
carried 231. They spilled 112!
1. Select the equation that tells how
many more they need to carry?
2. Select the equation that uses
front end estimation to check.