80

90

94

96

©Laura Graham ~ Where the Magic Happens Teaching

A benchmark number is a 10 or a decade number like 1, 20, 30, 40, etc. A benchmark number can also be a 100 like 200, 300, 400, 500, etc.

Benchmark Numbers

Name

SORT Cut the numbers at the bottom and classify between benchmark and not benchmark. BENCHMARK

NOT BENCHMARK

©Laura Graham ~ Where the Magic Happens Teaching

23

459

410

60

500

98

237

200

384

390

547

674

600

320

254

690

714

700

40

60 218

200

80

?

223

120

140

244

?

250

160 261

180

?

272

200 293

?

300

©Laura Graham ~ Where the Magic Happens Teaching

You can estimate “friendly” numbers by looking at the other numbers around them.

Benchmark Numbers

Name

ON A NUMBER LINE Estimate the number in the label on the following open number lines.

300

500

0

311

389

345

518

600

533

18

29

72

100

881

800 ©Laura Graham ~ Where the Magic Happens Teaching

400

900

2+8

8+2

6+1

3+5

©Laura Graham ~ Where the Magic Happens Teaching

There are combinations that make a 10. It is important to be able to identify them to see the parts of a whole.

10+90=100

2+8=10

20+80=100

3+7=10

30+70=100

4+6=10

40+60=100

5+5=10

50+50=100

6+4=10

60+40=100

7+3=10

70+30=100

8+2=10

80+20=100

9+1=10

90+10=100

©Laura Graham ~ Where the Magic Happens Teaching

1+9=10

100+900=1,000

20+80=100

200+800=1,000

30+70=100

300+700=1,000

40+60=100

400+600=1,000

50+50=100

500+500=1,000

60+40=100

600+400=1,000

70+30=100

700+300=1,000

80+20=100

800+200=1,000

90+10=100

900+100=1,000

©Laura Graham ~ Where the Magic Happens Teaching

10+90=100

35+15+22+48= 30+10+5+5 40+10 =50

20+40+2+8 60+10=70

56+13+24+47 50+20+6+4 60+10=70

10+40+3+7 50+10=60

©Laura Graham ~ Where the Magic Happens Teaching

Start by grouping the pairs that make a benchmark first! Look at the digits in the ones place, and find the combinations that make a 10!

Name

Benchmark Numbers

TO ADD ON A NUMBER STRING

Solve the following addition problems, use your knowledge of property of operations and benchmark numbers to solve. 78+46+12+24=

15+93+65+73=

©Laura Graham ~ Where the Magic Happens Teaching

61+82+39+58=

44+83+16+27

If you liked this my other math

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