In medium to large bowl mix Lime Jell-O per package directions. Go a little scant on the water due to moisture in Carrots and Grapes. Place in 9" by 13" cake pan or Glass casserole dish.
Rinse,pare and shred Carrots. Rinse Seedless Grape (Red or White), then quarter. Add Carrots and Grapes to Jell-O and stir.
Refrigerate until Jell-O sets. When it starts to get a little wobbly stir to bring ingredient from bottom. Allow to cool and set.
To serve slice into squares. Add Cool Whip or a dab of Ice Cream if you wish.
If you encounter any reluctance with the youngsters, press a single M & M to the center of the square and suggest with "Authority" that they eat their way to the center to retrieve. THIS PLOY WORKS -- SOMETIMES. If you use Orange Jell-O they may not even notice the Carrots.
Note: If for toddlers omit the nuts and maybe chop the grapes finer. Peace!
Hint: I've had times when the Jell-O just doesn't set up and firm. In this case I salvage by adding an additional box of Jell-O using 1/2 to 1/3 the recommended water. Using very hat water I disolve well and stir and completely incorporate into the failed batch. It works.