Idea 4of 23Builds onPrice ÷ how many, not the other way
The price for 100 g
How do you find a unit price for food sold by weight?
Today you'll discover
- why stores use 100 g
- how many 100 g parts a pack holds
- how to divide by them
Think first500 g of cheese for $6.00
A 500 g block of cheese costs $6.00. What does 100 g of it cost?
Decide first, then press Next. Count how many 100 g parts the pack holds.
A 500 g block of cheese with a tag: $6.00. Then a bar cut into 5 equal parts, with the line 500 g = 5 × 100 g; then $6.00 ÷ 5 = $1.20 in each part and on the tag as $1.20 / 100 g; then the check 5 × $1.20 = $6.00. The last step asks about 700 g of cereal for $6.30.
See the whole ideathe big idea and the key word, in one place
The big idea
Count the 100 g parts in the pack, then divide the price by that number.
How many 100 g parts?
200 g is 2 parts, 500 g is 5, 700 g is 7. Drop the two zeros to count the hundreds.
- 200 g2 parts
- 500 g5 parts
- 700 g7 parts
Easy to get wrongDo not divide by 100 or by 500. Divide by how many 100 g parts there are: for 500 g, that is 5.
Key word
- per 100 g
- for every 100 grams: $1.20 per 100 g means each 100 g costs $1.20
Ready to use it?
- Find a price per 100 g.
- Count the 100 g parts in a pack.