1. (2024一下·临平期末) 口算

15+2=	54-4=	( )+9=24	76-5+9=
50-10=	9+20=	90-( )=30	98-6-30=( )
8+7=	77-20=	8+( )=68	23-(5+4)=
47-8=	90-7=	( )-6=17	20+(7+60)=
43-3=	60-8=	( )+80=100	30-(12-5)=