60) Fluency Doubles

Doubling and Halving to 20: Racing Kayaks

60.1 Fluency Doubles Racing Kayaks


Develop fluency with double bonds for the wholes 12, 14, 16, 18, 20.

Prior knowledge of ten plus bonds and part-part-whole is required.


  • double bond: a two-part bond, where both parts are the same
  • double
  • equals as “is”


A little easier

Use Bond Blocks

Place the following blocks in a jumbled pile within reach of both players:

  • One 2 and one 4 block.
  • Two 6, 7, 8, 9, 10 blocks.

Allow students to build a part-part-whole diagram, as needed, for unknown double bonds. Often in the process of picking up the blocks students remember the bond. Touching the blocks gives processing time. Allowing students to build the whole provides reassurance and reduces anxiety. 

Part-Part-Whole diagrams

Click to download the Double Bonds to 20 Part-Part-Whole Diagrams

These part-part-whole diagrams  can be stuck to the top of student’s desk, as a desk visual, until students are fluent recalling these facts. Students with memory or processing difficulties can benefit from having visuals as permanent prompts.

Click this link to read Teacher Notes for more ideas about “Using Part-Part-Whole Desk Visuals” to support students.


In the next activity, students repeat this fluency activity, but do so using one half of a double bond. Go to

Activity 61

Doubling and Halving to 20: Fluency Halves, Racing Snowboards