One stroke per sentence: draw a bar model to sort out how the unknowns relate, then move step by step to shorter symbols.
- 1Sum and Difference Problems9:49
- 2Sum and Difference with Multiples9:47
- 3Elimination5:59
- 4Substitution4:24
- 5Writing Equations5:46
- Now playing: 6Solving for a Group4:18
Relationships between Unknowns: Solving for a Group
Methods in this video
Tap a time to jump to where the video teaches that method.
- 1
Asked for a group? Build the group
When to use it: You are given totals of groups (several scales, each with a mix) and asked for another group. You don't need each single value, and it may be hard to find.
- Asked for a group? Don't find each one yet. Count how many of each you have.
- Make the thing you don't want match on both sides, then subtract whole groups.
- Do the same to the totals.
Practise exam-style questions with these methods
Free 7-day trial, no credit card required.