The teaching strategy 'Phonics' is the explicit teaching of the rules by which the sound a word makes can be worked out from the letters which comprise it.  This is done in stages.  First students are taught the sounds that individual letters make. This is known as the letter-sound correspondence.  Then students are taught the sounds that small groups of letters make ('th' , 'ch' etc)  This is referred to as grapheme-phoneme correspondence. The last stage is to combine a series of sounds (phonemes) into words. This last stage is refereed to as blending. 

Blending is difficult because the combination of two phonemes into a single sound is not achieved by saying one phoneme then immediately saying the other:  'bl' is not just 'b' followed by 'l'.  The start of  'bl' recognizably comes from 'b' and the end recognizably comes form 'l' but the combination is a new phonetic entity.  Making the leap from 'b' 'l' to 'bl' is the biggest challenge in learning to read.

It is beyond dispute that in any alphabet based orthography, the ability to read depends on phonics mastery i.e. the internalisation of the letter-sound correspondences of that particular alphabet. The educational publishing industry has responded magnificently to this challenge by producing a range of very creditable, well researched and professionally produced resources which are widely and very successfully used in schools all around the world. There is good evidence that this strategy is extremely productive with the vast majority of children. The same evidence, however, suggests that this teaching approach consistently fails some 15% of children. If we are to succeed with those last 15% of students it follows that we have to examine what it is that goes wrong in conventional teaching methods.

As noted above the limiting factor with a phonics based approach is not the process of decoding but rather the process of blending, which must follow decoding if it is to turn into reading.   So can we teach the rules of blending in the same way we teach the grapheme-phoneme correspondences?   No. The problem with blending is one of sheer scale: there are relatively few graphemes and phonemes but an almost unlimited number of possible blends.     It is just not practicable to teach all the rules of blending and in the end children have to develop an intuition based on experience.

It as at the 'blending' component of  phonics that the Literacy Toolbox is aimed and it is in this area where students experience most benefit using the Literacy Toolbox.