Ten Plus Bonds: Strategy 9+

Mathematics

Develop the addition strategy of bridging ten, from a part of nine, for wholes up to 20.

For example, to solve 9 + 7

Prior knowledge of part-part-whole, bonds of 10 and place value partitioning using ten plus bonds is needed.

Language

• bridge ten
• equals
• sum: the total resulting from addition

Differentiation

A little easier

Counting order

Calculate each question in counting order, working clockwise around the spinner, from the 12 o’clock position. Do not flick the spinner. Assist students to identify patterns.

Use Bond Blocks

If students have difficulty partitioning the second part, into one plus another part, use an additional block.

For example, to model 9+7

Some students find it conceptually easier to first place the 9 and 7 blocks. Then place the 1 and 6 on top of the 7 block.

• From a top view they can see the bridging ten partition, 9 + 1 + 6.
• From a front view they can see the parts of 9 and 7.

A little harder

Play “Ten Plus Bonds: Bridging Ten Addition Strategy 19+ a little harder”.  In this game students have to bridge ten, to twenty, from a part of 19, for wholes up to 30.

Reduce scaffolds

The blocks are a scaffold to support calculation. If students can calculate without some or all of the blocks encourage this. Below is a progression of reducing scaffolding, from most to least support, using bridging ten for 19 + 7.

Progression

In the next activity students extend bridging 10 to adding a part of 8. Go to

Activity 51

Ten Plus Bonds: Bridging Ten Addition, Strategy 8+