Take a look at the following label:

It says there are 549 calories per 100g

The bar is only 40 grams

**So multiply the calories per 100g by .40 (point 40) like this:**

**549 x .40 = 219 cals**

Therefore if you know the 100 grams then you can multiply the amount you eat by using the decimal point – simply move the decimal point as follows:

Lets suppose the food is **50 calories per 100 grams** (you will find how many calories are in 100 grams from either the label or online). Then:

if you eat 350 grams you would multiply 100 grams by 3.5

50 cals x 3.5 = 175 cals

if you eat 35 calories you would multiply 100 grams by .35

50 cals x .35 = 17.5 cals

if you eat 200 grams you would mutliply 100 grams by 2.0

50 cals x 2.0 = 100 cals

if you eat 455 grams you would multiply 100 grams by 4.55

50 cals x 4.55 = 227 cals

and so on. Do you get the idea?

### Now try it yourself

you read on the label that there are 75 calories per 100g

you eat 125 gms

how many calories did you eat?

*ANSWER: 94 CALORIES*

*(75 cals x 1.25 = 94 cals (actually the answer was 93.75 so I rounded it to 94.)*