adding up. category 1 adding up strategy : the whole number is a multiple of ten or one hundred. the...

ADDING UP

CATEGORY 1

Adding Up strategy :The whole number is a multiple of ten or one hundred.The subtrahend is close to a multiple of ten or a landmark number.

20 – 1520 – 1420 – 920 – 8

30 – 2430 – 1930 – 1530 – 12

40 – 3440 – 2940 – 2440 – 19

50 – 4450 – 3950 – 2950 – 24

60 – 5460 – 4960 – 3960 – 29

70 – 5970 – 4970 – 3970 – 34

80 – 6980 – 5980 – 4980 – 39

90 – 7990 – 7490 – 4990 – 44

100 – 89100 – 74100 – 49100 – 44

CATEGORY 2

Adding Up strategy :The whole number is a multiple of ten or one hundred.The subtrahend is close to a multiple of ten or a landmark number.

100 – 89100 – 69100 – 49100 – 37

150 – 124150 – 149150 – 124150 – 99

250 – 224250 – 219200 – 199200 – 149

300 – 269300 – 249300 – 99

300 – 149

400 – 349400 – 299400 – 274200 – 199

500 – 449500 – 419500 – 299500 – 249

750 – 709750 – 599750 – 449750 – 324

1000 – 8991000 – 7491000 – 6241000 – 499

CATEGORY 3

Adding Up strategy :The whole number is NO longer an exact multiple of ten or one hundred.The subtrahend is farther distance from the whole.

50 – 2950 – 2950 – 4850 – 37

80 – 5984 – 5981 – 4881 – 36

70 – 4973 – 4976 – 6776 – 39

100 – 75120 – 75125 – 75125– 83

100 – 80140 – 80146 – 80146– 89

200 – 149250 – 149223 – 186245– 198

300 – 174315 – 174335 – 219335– 287

400 – 329420 – 329423 – 318444 – 298

500 – 249525 – 249

1000 – 4991000 – 671