有一堆粗细均匀的圆木，堆成梯形，最上面的一层有3根圆木，每向下一层增加一根，最下面的一层有22根圆木，一共堆了20层，这堆圆木一共有多少根？
直接写得数．×16= 12÷= 24×=×÷= 1÷=÷15=÷=×÷×=
口算我最棒= 26×======= 6.4÷20%= 125%×8=
直接写得数． 10÷=÷=×= 55×÷=×2= 1÷=÷= 0×+=
口算×15=×2=×=×=÷=÷3=÷5=÷=
直接写得数 24×= 72×= 12÷=÷3= 0÷= 3÷=×=﹣×0=
×16= 12÷
= 24×
=
×
÷
=
÷15=
÷
=
×
÷
= 26×
=
=
=
=
=
=
= 6.4÷20%= 125%×8=
=
÷
=
= 55×
÷
=
×2= 1÷
=
÷
= 0×
+
=
×15=
×2=
×
=
×
=
÷
=
÷3=
÷5=
÷
=
= 72×
= 12÷
=
÷3=
= 3÷
=
×
=
×0=
粤公网安备 44130202000953号