Big Idea There is more than algorithm for each of the operations with rational numbers. Most algorithms for operations

with rational numbers use both mental math and paper and pencil.

Essential Understanding/Question17 -1How can you use mental math to add multiples of 100 to a three-digit number?

Build, draw, or write to find the missing addend using your choice of one of the

problems in the box.

Describe how you used mental math to find the missing addend in one of the problems in the middle box?

Cre

ate

a st

ory

with

a 3

or

4 di

git

num

ber

that

you

are

jo

inin

g to

a 3

dig

it nu

mbe

r w

ith a

zer

o in

the

ten

s an

d th

e on

es p

lace

.

Create your ow

n 3 or 4 digit number sentence adding

a 3-digit number that has zeros in the tens and ones

place.

32 + ______ = 232496 + _____ = 996_____ + 400 = 782

3, 429 + ______ = 3, 729

17 - 1

Big Idea Numbers and calculations can be approximated by numbers that

are close and easy to compute mentally. (17-2)

Essential Understanding/QuestionHow can you estimate sums of three-digit numbers?

Show two different ways to estimate the sum.

How does estimating help you find a reasonable answer.

Cre

ate

a n

addi

tion

wor

d pr

oble

m u

sing

an

estim

atio

n st

rate

gy.

Explain how

you estimated to find the sum

.

How can you estimate sums of one of the

following problems.423+187

1,423+2, 370(17-2)

There is more than algorithm for each of the operations with rational numbers. Most

algorithms for operations with rational numbers use both mental math and paper and pencil.

Essential Understanding/Question

17-3How can you model and record adding 2 three-digit

numbers?

Draw, build, or write an addition sentence using 2 three-digit numbers.

Find the sum of 2,743 and 397.

Cre

ate

an a

dditi

on s

tory

usi

ng 2

thr

ee-d

igit

num

bers

th

at r

equi

res

regr

oupi

ng.

Explain w

hy you did or did not have to regroup.

How can you model and record adding 2 three-

digit numbers?

17 - 3

Big Idea There is more than one algorithm for each of the

operations with rational numbers. (17-4)

Essential Understanding/QuestionHow do you add three-digit numbers using paper and pencil?

Draw or write how to regroup the problem you chose.

Show another way to solve the problem you chose.

Cre

ate

a w

ord

prob

lem

usi

ng t

he n

umbe

r yo

u ch

ose.

Explain how

regrouping is used to solve this problem.

Your Choice369+531

1,522+478(17-4)

Big IdeaThere is more than algorithm for each of the

operations with rational numbers. Most algorithms for operations with rational numbers

use both mental math and paper and pencil.

Essential Understanding/Question

17 – 5What strategy can you use to find the missing part?

Draw, build, or write one way to solve one of the problems in the box.

Find the missing part of one of the problems in the box.

Cre

ate

an a

dditi

on s

tory

pro

blem

tha

t m

atch

es o

ne o

f th

e nu

mbe

r se

nten

ces

in t

he b

ox.

Explain how

you solved one of the problems in the

box.

400 + _____ = 860460 + ______ = 930

_______ + 370 = 560______ + 2,100 = 4, 310

17 - 5

Big IdeaNumbers and calculations can be approximated by numbers that

are close and easy to compute mentally.( 17-6)

Essential Understanding/QuestionHow can you estimate differences of three-digit numbers.

Show how you would estimate to find the difference of one of the problems.

How does estimating help you find a reasonable answer.

Cre

ate

a su

btra

ctio

n w

ord

prob

lem

usi

ng a

n es

timat

ion

stra

tegy

.E

xplain how you estim

ated to find the difference.

Your Choice769-227

3,105-1,638(17-6)