Question Video: Modeling Place Value of Two-Digit Numbers with Part-Whole Models Mathematics • Second Year of Primary School

Video Transcript

Find the missing part. Is it five, 50, or eight?

We’re shown a part–whole model. The number 85 is the whole number. It’s a two-digit number. It has a tens digit and a ones digit. This part of the number is the tens part. The number 85 has eight 10s. We can model eight 10s using eight 10s blocks. Let’s count in 10s. 10, 20, 30, 40, 50, 60, 70, 80. The eight digit in the number 85 is worth 80. And the five digit in the number 85 is worth five ones. 80 plus five is 85.

The missing part of the number is five. 85 has eight 10s, which are worth 80, and five ones.