Blocks from tutorials not available in new project

Hi, I am working with sixth graders. They have done tutorials but it is frustrating that when they want to make their own projects to apply those skills, the same blocks are not available when they start a “New Project.” For example, the Monster Truck tutorial uses acceleration, but I can’t find a block that would let me change “set vx” to set “ax” Please help. Thanks

Its in the dropdown when settihg or changing a sprite’s x or y position