Hi, I am a primary sch teacher (also at the Yew Tee area) and I'm somewhat involved with the school's AVA Club. At the primary school level, get a good compact. As some have mentioned, a Canon S5IS, or even a Canon Powershot A650IS.
IMO, a DSLR is too advanced for a primary 4 child. There's also the worry that the child may be spoiled and get the wrong impression that for good pics, must have good camera/DSLR.
Starting from a compact is good because of its limitations. The child will learn to work around the limitations and this alone will improve his/her skills. (And if you're really brave and/or serious, when he gets to sec sch, get him/her a film camera.)
Also, I don't think it's necessary for primary school students to own a DSLR. If need be, the school should provide such expensive equipment. (Nowadays, schools are given a huge budget and they've got a lot of money to buy stuff)