Problem
Split a whole into proper-fraction portions
Jisoo has 187/20 kg of strawberries. She packs them into 2 kg boxes. We need to count how many complete 2 kg boxes she can fill and sell.
FractionsOperations
Your answer
boxes
Watch out It's tempting to round 9.35 ÷ 2 ≈ 4.7 up to 5 boxes, but a box only counts if it is completely full.
How to solve
Strategy Solve an Easier Related Problem — Turn the improper fraction 187/20 into an easier decimal weight, then repeatedly take away 2 kg (one box at a time) and count how many full boxes come out before less than 2 kg remains.
1STEP 1
Write the total weight in an easier form
Change the improper fraction 187/20 into a decimal so the weight is easy to picture: 187 divided by 20 is 9.35.
187/20 = 9.35 kg
Seeing 187/20 as 9.35 kg lets a young learner reason with a familiar weight instead of a scary fraction.
3.NF.A.1Solve An Easier Related Problem2STEP 2
Take away 2 kg for each box
Each box uses 2 kg, so count whole groups of 2 kg inside 9.35 kg: 2, 4, 6, 8 kg fills 4 boxes, but 10 kg is too much.
2 + 2 + 2 + 2 = 8 kg, which is not more than 9.35 kg, and 9.35 kg is less than 10 kg
Repeatedly subtracting 2 kg is just sharing the strawberries into equal 2 kg boxes.
3.OA.A.2Look For A PatternThe number of full 2 kg boxes is the same as how many whole groups of 2 kg fit inside 9.35 kg.
Why?
Each box holds exactly 2 kg, so filling one box takes one whole 2 kg group out of the total, and every box takes the same 2 kg.
Why?
Making the boxes stacks 2 kg over and over, so the count of boxes is just how many 2 kg groups the total is built from.
🧱Multiplication as equal groupsa times b means a equal groups of b — it is just repeated adding of the same amount.
Why?
Taking 2 kg away again and again to count the boxes is the reverse of stacking 2 kg to build them, so both ways reach the same count.
🧱Inverse operationsSubtraction undoes addition and division undoes multiplication — they reverse each other.
3STEP 3
Count full boxes and check the leftover
After 4 boxes (8 kg), 9.35 - 8 = 1.35 kg is left — less than 2 kg, so no more full boxes. She can sell 4 boxes.
9.35 - 8 = 1.35 kg, which is less than 2 kg
A box must be full to be sold, so the leftover that is not enough for a whole box does not count.
3.OA.A.2Solve An Easier Related ProblemAnswer
4 boxes
9.35 kg of strawberries in 2 kg boxes should be about 9.35 / 2 = about 4.7 boxes, and only whole full boxes count, so 4 boxes is the right size answer.
Takeaway
Once 187/20 is written as 9.35 kg, this only needs Grade 3 sharing-into-equal-groups sense: keep taking out 2 kg until less than 2 kg is left!
- Write the total weight in an easier form
- Take away 2 kg for each box
- Count full boxes and check the leftover
Where next?
Level upsuggested
Another one like thissuggested
Step back and solidifysuggested