This is a song to teach by rote; at the end of it you sing up the scale 1 2 3 4 5, and back down 5 4 3 2 1.
Once this is secure, you can then choose a floor; eg 3; and sing 1 2 3; 3 2 1; 1 3 1
It is useful for teaching the intervals of a major scale, and also for singing cleanly from one note to the next. Some practical exam aural tests require recognition, or singing, of intervals and this song is a good place to start.
When the first five notes of the scale are perfect every time, increase the number of floors to the full octave; 1 2 3 4 5 6 7 8. Just be careful trying to go straight to number 7; that’s a bit tricky!