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Finding Products
Comparing Expressions
Standard Algorithm
Estimation
Decimal Multiplication
100

31 x 7 =

217

100

(8 + 12) x 15  _______  51 x (12+8)

(8 + 12) x 15  < 51 x (12+8)

100

431 x 12

5,172

100

22 x 2.4 

20 x 2 = 40

100

1.21 x 14 = 

1.21 x 14 = 16.94

200

31 x 70 =

2,170

200

18 x 27 ___ 20 twenty sevens minus 1 twenty seven

18 x 27 < 20 twenty sevens minus 1 twenty seven

200

123 x 23

2,829

200

3.2 x 47 =

3 x 50 = 150

200

2.45 x 305

747.25

300

310 x 70 =

21,700

300

24 x (20+5) _____ (20=5) x 12

24 x (20+5) > (20=5) x 12

300

476 x 65

30,940

300

8.2 x 34

8 x 30 = 240

300

7.06 x 28 =

1468.48

400

310 x 700 = 

217,000

400

19 x 9 ___ 3 nineteens, tripled

19 x 9 = 3 nineteens, tripled

400

481 x 302

145,262

400
14.6 x 17

10 x 20 = 200

400

6.32 x 223

1,409.36

500

3100 x 700 =

2,170,000

500

The difference between 20 threes and 4 threes

___________________

The sum of 6 threes and 12 threes


The difference between 20 threes and 4 threes

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The sum of 6 threes and 12 threes

500

8,401 x 305

2,562,305

500

160.4 x 17

200 x 20 = 4,000

500

151.46 x 555

84,060.30