One school principal is not phased by mistakes being found in a Ministry maths resource book. 

18 errors have been found and fixed - including incorrect sums and a Te Reo Māori typo.

Auckland Primary Principals' Association President Lucy Naylor says it's not ideal, but the resources only make up about five percent of what's taught.

She points out they didn't cost schools.

"Given the maths resources have been given free to schools by the Government, it kind of outweighs the errors."

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