Unit 9

Vocabulary

100

numbers added together are called 

addends

200

the answer to an addition problem

sum

300

Adding digits one place value at a time gets you a ________

partial sum

400

When you _______ a number you break it apart by place value 

decompose 

500

______ numbers is a way to make them friendlier to add

adjusting 

Decompose

100

decompose 567 

500+60+7

200

decompose 683

600+80+3

300

decompose 400

400+0+0

400

decompose 301

300+0+1

500

decompose 610

600+10+0

Adjust

100

adjust the following numbers to make them friendly:

458+322

458+2= 460

322-2+320

200

adjust the following numbers to make them friendly:

144+126

144+1=145

126-1=125

300

adjust the following numbers to make them friendly:

425+236

425+5= 430

236-5= 231

400

adjust the following numbers to make them friendly:

99+91

99+1=100

91-1=90

500

adjust the following numbers to make them friendly:

622+438

622+3=625

438-3= 435

Add the Partial Sums

100

100+200=

40+30=

1+4= 

300+70+5= 375

200

400+200=

60+20=

5+3=

600+80+8= 688

300

300+100=

30+50=

7+2=

400+80+9=489

400

500+100=

70+10=

6+3=

600+80+9=689

500

300+500=

20+70=

3+5=

800+90+8=898