Solve Decimal Addition: 123.421 + 615.3 Step by Step

To avoid confusion in solving the exercise, we will first add two zeros to the number 615.3 as follows:

$123.421\\+615.300\\$

Now let's solve the exercise in order:

Let's connect the thousandths after the decimal point:

$1+0=1$

Let's connect the hundredths after the decimal point:

$2+0=2$

Let's connect the tenths after the decimal point:

$4+3=7$

Finally, let's connect the whole numbers before the decimal point accordingly:

$3+5=8$

$2+1=3$

$1+6=7$

And we obtain the following:

$123.421\\+615.300\\738.721$