Addition formula within 10

1+ 1= 2

1+ 2= 3 2+ 2= 4

1+ 3= 4 2+ 3= 5 3+ 3= 6

1+ 4= 5 2+ 4= 6 3+ 4= 7 4+ 4= 8

1+ 5= 6 2+ 5= 7 3+ 5= 8 4+ 5= 9 5+ 5= 10

1+ 6= 7 2+ 6= 8 3+ 6= 9 4+ 6= 10 5+ 6= 1 1 6+ 6= 12

1+ 7= 8 2+ 7= 9 3+ 7= 10 4+ 7= 1 1 5+ 7= 12 6+ 7= 13 7+ 7= 14

1+ 8= 9 2+ 8= 10 3+ 8= 1 1 4+ 8= 12 5+ 8= 13 6+ 8= 14 7+ 8= 15 8+ 8= 16

1+ 9= 10 2+ 9= 1 1 3+ 9= 12 4+ 9= 13 5+ 9= 14 6+ 9= 15 7+ 9= 16 8+ 9= 17 9+ 9= 18

1+ 10= 1 1 2+ 10= 12 3+ 10= 13 4+ 10= 14 5+ 10= 15 6+ 10= / kloc-0/6 7+ 10= 17 8+ 10= 18 9+ 10= 19

10+ 10=20

Add the formula within 20 minutes.

1+ 1 1= 12 2+ 1 1= 13 3+ 1 1= 14 4+ 1 1= 15 5+ 1 / kloc-0/= 16 6+6543 8+0 1= 17 7+ 1 1= 18 8+ 1 1= 19 9+ 1 1=20

1+ 12= 13 2+ 12= 14 3+ 12= 15 4+ 12= 16 5+ 12= 17 6+ 12= 18 7+ 12= 19 8+ 12=20

1+ 13= 14 2+ 13= 15 3+ 13= 16 4+ 13= 17 5+ 13= 18 6+ 13= 19 7+ 13=20

1+ 14= 15 2+ 14= 16 3+ 14= 17 4+ 14= 18 5+ 14= 19 6+ 14=20

1+ 15= 16 2+ 15= 17 3+ 15= 18 4+ 15= 19 5+ 15=20

1+ 16= 17 2+ 16= 18 3+ 16= 19 4+ 16=20

1+ 17= 18 2+ 17= 19 3+ 17=20

1+ 18= 19 2+ 18=20

1+ 19=20

Subtraction formula within 10

9-9=0 9-8= 1 9-7=2 9-6=3 9-5=4 9-4=5 9-3=6 9-2=7 9- 1=8

8-8=0 8-7= 1 8-6=2 8-5=3 8-4=4 8-3=5 8-2=6 8- 1=7

7-7=0 7-6= 1 7-5=2 7-4=3 7-3=4 7-2=5 7- 1=6

6-6=0 6-5= 1 6-4=2 6-3=3 6-2=4 6- 1=5

5-5=0 5-4= 1 5-3=2 5-2= 1 5- 1=4

4-4=0 4-3= 1 4-2=2 4- 1=3

3-3=0 3-2= 1 3- 1=2

2-2=0 2- 1= 1

1- 1=0