Foundation
USE WHEN
A total is divided into groups and subgroups with different percentage conditions.
BEST METHOD
Tree Diagram Method
TARGET
60–90 sec
MASTERY
not started
A total is divided into groups and subgroups with different percentage conditions.
Use a percentage tree or one-variable equation to avoid unnecessary intermediate totals.
Normalize total to 100 when only ratios/percentages are required.
Branch the total into groups and subgroups using percentage multipliers.
Timed drill
Identify the base or invariant before you calculate.
Attempt first · Standard Example
Attempt first · CAT-Level Example
3-level practice ladder
Foundation
CAT Standard
Advanced / Hybrid
cat 2020 slot 1: young/old and literate/illiterate percentage distribution. also cat 2024 slot 3 uses boys/girls with swimming/running percentages.