how many
<a href="https://scienceres-edcp-educ.sites.olt.ubc.ca/2013/08/25/measurement-mass-ii/" title="Measurement: Mass II"><img src="https://scienceres-edcp-educ.sites.olt.ubc.ca/files/2013/08/elem_math_shape_mass2-150x150.jpg" alt="Measurement: Mass II" class="thumbnail thumbnail " /></a>