Is gravity stronger nearer earth's core or is it weaker

I read a book where these kids are floating around in the earth's crust and i wanted to know if this is even remotely possible.

Gravity is the strongest at the surface of Earth. Above or below it , it gets weaker and weaker. Remember, gravitational attraction is due to the mass contained inside the sphere ( with radius equal to the position of observer from the center of earth, and the center of earth coinciding with center of that circle). I'll put it in simple words....gravity will be due to the mass of earth BELOW the observer (in your case it is the core...so if they are at the exact center of earth ...they will experience NO gravity) ....the farther you move away from the center...you will experience gravity due to the sphere below you(with its radius being equal to the distance between you and the center). Hope you understood.

Gravity remains more or less constant initially. Why? We still can neglect the mass outside the radius when heading for the centre - this is decreasing the gravity. But we also come closer and closer to the very dense core - this is increasing the gravity. Both are of about the same magnitude initially, cancelling each other. (note that in the initial stage, entering the (relatively very light) crust the gravity increases sharply from 9.81 to 9.96 ms-2)

Coming closer to the the core however, the increasing factor wins and my model indicates a maximum value of 10,62 ms-2 at the core mantle boundary versus 9,81 at the Earth surface. Njorl predicted that more or less correctly.

The earth's crust is the surface of the earth, and the gravity there is what it is, 9.8 m/s².

As you go deep into the earth, the gravity starts to decrease, reaching zero at the center.

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gravity would be weaker at the core. temperature would be intense, the crust of the earth is the outer part tho.

I believe it's stronger nearer the earth's core.