your link isn’t working for me. But it sounds like you have a typical older 10-speed bike.

you keep pedaling while you shift.

One easy way to decide this is to know your gear ratios. To figure out which gear you want, take a couple minutes and do this math calculation: (it’s easy, really.)

for each of the 10 possible combinations of gears, you just calculate a number, with is the number of inches that the bike will move forward every time your feet move one full rotation of the pedals.

The numbers will be between approx 30 and 100. Obviously, you have to use about 3 times more muscle power to move forward 100 inches than 30 inches

So the “100” gear is the hardest one on your legs.Use it when you are going downhill. The “30” gear is the easiest one to pedal–use it when you are going up a steep hill. The “60” gear is in the middle and good for flat ground, etc…

Now do the math:

First–count the number of teeth on each of the 5 rear sprockets and the 2 front ones.(you may have to get one finger greasy, and rotate the chain a bit to make sure you see all the teeth.)

Now divide the front number by the rear number, and the multiply it by 27 (assuming your bike has 27inch diameter wheels)

For example : the larger front ring of ,say,52 divided by a rear 14 equals 3.7 , times 27 equals 100. A nice gear for going downhill.

The smaller front, say 43, divided by a larger rear gear (say 27) equals 1.6, times 27 equals 43. This is a good gear for saving muscle power for each rotation of the pedals, so use it for going uphill. (the tradeoff is that you will not go as fast, and will need to pedal more rotations to cover the same distance. )

write it all down once, but don’t worry about using all 10 combinations at first.You’ll have trouble memorizing it all (gee…which is the lower number: high front sprocket with gear number3 in the rear, or low with gear number 4, or vice-versa, etc)

Just pick 3 or 4 options (for uphill, downhill and flat) and use them only. After a while, you’ll get used to it, and it will be easier to remember the whole sequence and you can be more picky about selecting any of the 10 gears.