you use multiplication by sevens.
Chat with our AI personalities
How do you count by sevens
skip all the 8's
7*9 is 63. You can count seven nines or nine sevens, or you can use a calculator.
7,17,27,37,47,57,67,70,71,72,73,74,75,76,77(two sevens),78,79,87,97=20 times
there are four sevens in 28.