3.
1 + 9 = 10
2 + □ = 10
3 + □ = □
4 + □ = □
5 + □ = □
□ + □ = □
□ + □ = □
□ + □ = □
□ + □ = □
1 + 9 = 10
2 + □ = 10
3 + □ = □
4 + □ = □
5 + □ = □
□ + □ = □
□ + □ = □
□ + □ = □
□ + □ = □
答案：
1 + 9 = 10
2 + 8 = 10
3 + 7 = 10
4 + 6 = 10
5 + 5 = 10
6 + 4 = 10
7 + 3 = 10
8 + 2 = 10
9 + 1 = 10
1 + 9 = 10
2 + 8 = 10
3 + 7 = 10
4 + 6 = 10
5 + 5 = 10
6 + 4 = 10
7 + 3 = 10
8 + 2 = 10
9 + 1 = 10
4. $3+7=$ $10-1=$ $2+8=$ $5+5=$
$10-8=$ $1+9=$ $10-4=$ $10-7=$
$7+3=$ $4+6=$ $9-9=$ $10-5=$
$10-8=$ $1+9=$ $10-4=$ $10-7=$
$7+3=$ $4+6=$ $9-9=$ $10-5=$
答案：3+7=10 10-1=9 2+8=10 5+5=10
10-8=2 1+9=10 10-4=6 10-7=3
7+3=10 4+6=10 9-9=0 10-5=5
10-8=2 1+9=10 10-4=6 10-7=3
7+3=10 4+6=10 9-9=0 10-5=5
5. $□ + □ = 10$
$10 - □ = □$
$10 - □ = □$
答案：8+2=10 10-2=8
6. 圈一圈，填一填。
每个班分2个，够分给（
每个班分2个，够分给（
5
）个班。答案：
5
5