一、用凑十法做一做。
9 + 6 = 9 + 5 = 9 + 4 =
9 + 3 = 9 + 2 = 9 + 7 =
9 + 8 = 9 + = 8 + 8 =
8 + 7 = 8 + 9 = 8 + 6 =
8 + 5 = 8 + 4 = 8 + 3 =
7 + 9 = 7 + 8 = 7 + 7 =
7 + 6 = 7 + 4 = 7 + 5 =
6 + 9 = 6 + 8 = 6 + 7 =
6 + 6 = 6 + 5 = 5 + 9 =
5 + 8 = 5 + 7 = 5 + 6 =
4 + 9 = 4 + 8 = 4 + 7 =
3 + 9 = 3 + 8 = 2 + 9 =
二、填出括号里的数。
8+( )=10 10+( )=14 6+( )=15
( )+4=13 ( )+6=13 ( )+7=11
6+( )=14 ( )+9=12 8+( )=13
3+4-5=?????10-6+3=??????7-1+8=??????9-0-9=
( )-1=8 8-( )=6 ( )+3=9 2+( )=6
( )-2=6 7-( )=3 ( )+6=9 7+( )=10
( )-8=6 10-( )=7 ( )+6=10 2+( )=7
( )-2=7 14-( )=2 ( )+6=8 5+( )=9
( )-3=9 6-( )=1 ( )+4=7 4+( )=7