2想一想，算一算
(1) 34 + 5 = () )

想：先算 4 + () ) = () )
再算 30 + () ) = () )
(2) $34 + 50 = ( ) $ )$$$想：先算 $30 + ( ) $ ) = ($$) $ )$再算 $( ) $ ) + ($$) $ ) = ( ) $ )$
画一画，算一算
63+ 2 = ( ) )

(1) 39
想：先算 4 + 5 = 9
再算 30 + 9 = 39
(2) 84
想：先算 30 + 50 = 80
再算 80 + 4 = 84
画一画，算一算
63 + 2 = 65
（画图提示：在个位上画2个珠子，个位由3个珠子变为5个珠子，十位保持6个珠子不变）

算一算
$45 + 30 =$
$45 + 3 =$
$53 + 20 =$
$53 + 2 =$
$41 + 50 =$
$41 + 5 =$
$20 + 67 =$
$2 + 67 =$
$50 + 34 =$
$5 + 34 =$
$43 + 6 =$
$30 + 28 =$
$25 + 51 =$
$36 + 42 =$
$46 + 33 =$
$18 + 71 =$
$43 + 45 =$

45 + 30 = 75
45 + 3 = 48
53 + 20 = 73
53 + 2 = 55
41 + 50 = 91
41 + 5 = 46
20 + 67 = 87
2 + 67 = 69
50 + 34 = 84
5 + 34 = 39
43 + 6 = 49
30 + 28 = 58
25 + 51 = 76
36 + 42 = 78
46 + 33 = 79
18 + 71 = 89
43 + 45 = 88