The OnTrack Reading Phonics Program generally avoids the use of formal phonics rules. However, there is one rule that can help your child, especially when he is attempting to decode longer, multisyllable, words. The "Rule of c" covers the pronunciation of the letter "c", indicating when "c" stand for the /s/ sound.
The rule is: The letter c represents /s/ before the letters e, i or y; otherwise it represents /c/.
Here is a worksheet that you can use to help your child learn to apply the rule:
And here are several examples to show you how broadly useful this rule actually is.
cent: /s/ because it is followed by e
city: /s/ because it is followed by i
cyst: /s/ because it is followed by y
cat: /c/ because it is not followed by e, i or y
cot: /c/ because it is not followed by e, i or y
cut: /c/ because it is not followed by e, i or y
class: /c/ because it is not followed by e, i or y
cross: /c/ because it is not followed by e, i or y
back: /c/ because it is not followed by e, i or y (so the ck acts like kk)
scent: /s/ because it is followed by e (so the sc acts like ss)
since: digraph ce is /s/ because the c is followed by e
accuse: both /c/ because neither is followed by e, i or y (akkuse)
accent: first is /c/ but second is /s/ (ak-sent)
static: /c/ because it is not followed by e, i or y
Although the "Rule of c" is generally reliable, this is English, so there are some exceptions. In the United States, they are relatively few. "Soccer" would be pronounced sokser if it followed the rule and "muscle" would be muskle. And in British English, you will encounter a few spellings like "sceptic" whereas we in the US have changed the spelling to "skeptic" to comport with the rule.
Also, to follow the rule we even add the letter "k" to words like picnic and panic when adding a suffix starting with "e," "i" or "y," so we have picnicking, panicked and panicky.
The "Rule of c" can also be useful for spelling because it is so reliable. It turns out that we generally use the letter "k" when the letter "c" won't work because of this rule.
Next, The Sounds of the Letter g goes over a similar phonics rule for the letter "g," but also explains why it is less important to teach it. Or, you might prefer to look ever the OnTrack Reading Advanced Code Phonics Workbook that incorporates all of the lessons found in this section, and much more.