# Count

Count cells/ values if greater than

Count cells if contain negative numbers

Count cells if contain positive numbers

# Date

Restrict date to be entered and cell should only accept desired date (e.g Friday only)

# SUM

Subtotal invoices by age (datewise)

SUMPRODUCT Function (Multiply corresponding arrays, then return with the sum)

3D Sum for multiple worksheets

Sum if cells contain specific cells

Sum against single criteria in multiple columns

Sum if cells contain two specific texts (e.g. x and y)