口算、
12+4=________16-5=________16-2=________14+5=________
10+10=________2+15=________15+4=________19-3=________
3+16=________18-7=________13-2=________10+2=________
10+3=________15-4=________17-6=________10+8=________
9+5=________7+10=________3+9=________9+10=________