Count up to 50 objects by grouping the objects in tens.
Number Framework Stage 2
Many students will be able to read two-digit numbers but not realise that they represent ones and tens. This activity is designed to help them to learn this. In particular, many may not realise that “ty” at the end of words means “tens”. It is important that students learn to decode words like “sixty” as six tens.
Using materials
Problem: Your job at the factory is to bundle up felt pens and send them to the shops. Each bundle has exactly ten felt pens in it. At the end of the day, you have to write down how many felt pens you have packed.
Give pairs of students about fifty items of loose place-value material and get them to create bundles of ten.
Record the answers for all the pairs in a table.
Examples: Have the students repeat the grouping and recording of objects in ones and tens with other place-value materials.
Problem: Jerry has forty-three felt pens and Mark has thirty-four felt pens. Who has more felt pens?
Record 43 and 34 on the board or in the modelling book.
Have the students model both forty-three and thirty-four with bundled materials and discuss why forty-three is more.
Record “43 is more than 34” on the board or in the modelling book.
Examples: Word problems and recording for these pairs: Which number is larger: 56 or 65? 14 or 41? 25 or 52? 2 or 23? …
(For this problem in greater depth, see “The Bubblegum Machine”, Connected 2 1999.)