Both of these are divisable by 3 so this is what you should do first
$$\frac{813}{753651}=\frac{813\div 3}{753651\div 3}=$$
Or you could just do it on the calculator. A fraction line is the same as a divide by sign
so just enter 813/753651 into the home page3 calc and you will get
$${\frac{{\mathtt{813}}}{{\mathtt{753\,651}}}} = {\frac{{\mathtt{1}}}{{\mathtt{927}}}} = {\mathtt{0.001\: \!078\: \!748\: \!651\: \!564\: \!2}}$$
so the answer is 1/927
Both of these are divisable by 3 so this is what you should do first
$$\frac{813}{753651}=\frac{813\div 3}{753651\div 3}=$$
Or you could just do it on the calculator. A fraction line is the same as a divide by sign
so just enter 813/753651 into the home page3 calc and you will get
$${\frac{{\mathtt{813}}}{{\mathtt{753\,651}}}} = {\frac{{\mathtt{1}}}{{\mathtt{927}}}} = {\mathtt{0.001\: \!078\: \!748\: \!651\: \!564\: \!2}}$$
so the answer is 1/927