1. 直接写出得数。(每题 1★)
$11 - 3 = $ $12 - 9 = $ $11 - 4 - 3 = $
$15 - 6 = $ $17 - 8 = $ $14 - 7 - 6 = $
$13 - 5 = $ $13 - 6 = $ $18 - 6 - 7 = $
$16 - 7 = $ $14 - 5 = $ $12 - 4 + 5 = $
$10 - 8 = $ $16 - 9 = $ $13 - 7 + 9 = $
$12 - 5 = $ $15 - 9 = $ $16 - 8 - 8 = $
$6 + 8 = $ $12 - 7 = $ $5 + 8 - 6 = $
$10 - 4 = $ $9 + 4 = $ $7 + 5 - 3 = $
$11 - 2 = $ $12 - 6 = $ $14 - 5 + 4 = $
$14 - 7 = $ $15 - 8 = $ $6 + 4 - 1 = $
$18 - 9 = $ $13 - 4 = $ $15 - 7 + 9 = $
$11 - 8 = $ $17 - 9 = $ $5 + 9 - 4 = $

8 3 4 9 9 1
8 7 5 9 9 13
2 7 15 7 6 0
14 5 7 6 13 9
9 6 13 7 7 9
9 9 17 3 8 10

2. 连一连。(5★)