subtraction: adding up. category 1 the whole is a multiple of ten
TRANSCRIPT
Subtraction: Adding UP
Category 1
The whole is a multiple of ten.
20 – 1520 – 1420 – 1220 – 11
20 – 1020 – 920 – 720 – 8
30 – 2530 – 2330 – 1530 – 12
30 – 1930 – 1430 – 2430 – 21
40 – 3440 – 2940 – 2040 – 18
40 – 3240 – 2840 – 1940 – 24
50 – 3950 – 4450 – 2450 – 33
60 – 4960 – 2960 – 3960 – 19
70 – 5970 – 3470 – 4970 – 18
Category 2
The whole is a no longer multiple of ten but is below fifty.
15 – 915 – 915 – 915 – 9
21 – 1021 – 921 – 7 21 – 8
25 – 1925 – 1625 – 1825 – 9
23 – 1923 – 1623 – 1423 – 9
31 – 2931 – 2631 – 2431 – 15
32 – 2832 – 2532 – 1932 – 15
44 – 3944 – 3544 – 2944 – 25
41 – 3441 – 2841 – 2441 – 19
23 – 1933 – 1942 – 2941 – 18
Category 3
Mixture of numbers that lend themselves to the Adding Up Strategy
20 – 1424 – 1922 – 1326 – 17
30 – 1533 – 1933 – 1436 – 27
40 – 1945 – 1942 – 2342 – 34
50 – 2450 – 3956 – 2856 – 17
60 – 4960 – 2763 – 5663 – 19
70 – 6170 – 3474 – 4974 – 36
80 – 3980 – 6881 – 4981 – 58
90 – 7990 – 7492 – 8992 – 69
100 – 97100 – 89100 – 49100 – 24