FYI, I will try to answer your questions if you also give it a try.
Hope this blog can help the parents as well as the kids.
"A Model A Day, Keeps The Algebra Away" - Chi Hung Chan
Focus primarily on upper primary school (P4,5,6) mathematics
No guess and check, no wordy solution, just "Model" answer
My SIX STEPS TO MODEL APPROACH
A must visit website for Singapore PSLE
FYI, I will try to answer your questions if you also give it a try.
Hope this blog can help the parents as well as the kids.
A box contained 50¢ coins and 20¢ coins in the ratio 2:3. When I took out four 50¢, exchanged them for 20¢ coins, and put then put the money back into the box, the ratio became 2:7. Find the sum of money in the box.