图按照一定规律组成的三角形数阵，其中第一排有1个数，第二排有2个数，第三排有3个数，…，最后一排有10个数．如果把这55个数相加，问：所得到的和的十位数字是几?
直接写得数= 32×25%= 0.75+2.5= 3600÷30==×5= 0.32= 4×25﹣25= ×0.5=1 1÷10+0.9=（）×20==
直接写得数：+=÷= 1﹣5÷8=×=×= 0.9+99×0.9= 1÷0.6= 14÷35=÷×÷= 17.3÷1.73=
直接写出得数+=+=﹣0.125=﹣=+0.3= 10﹣=×=×=×= 10×=
口算：﹣=+=×= 25×10%=
直接写得数．﹣= 3+1=×6= 7.43﹣1.4﹣2.6= 1÷= 5.1+0.3= 0÷（﹣）= 25×4= 5.4÷0.3=
= 32×25%= 0.75+2.5= 3600÷30=
=
×5= 0.32= 4×25﹣25=
）×20=
=
+
=
÷
= 1﹣5÷8=
×
×
=
÷
+
=
+
=
﹣0.125=
﹣
=
+0.3=
=
×
=
×
=
×
= 10×
=
﹣
=
+
=
×
= 25×10%=
﹣
= 3+1
=
×6= 7.43﹣1.4﹣2.6= 1÷
=
﹣
）= 25×4= 5.4÷0.3=
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