Solve addition and subtraction problems using groups of ten.
Solve addition and subtraction problems by using place value partitioning.
Number Framework Stages 4 and 5
Ones and tens materials. E.g. sticks in bundles, BeaNZ, play money
Required Knowledge
Before attempting this activity check that the students can instantly recall the single digit subtraction facts.
Using Materials
Examples. Word stories and recording for: 45 – 20, 52 - 10, 42 – 20, 35 – 30, 63 – 50, 48 - 30....
Using Imaging
Shielding and Imaging Only: Examples. (Instant recall of single digit subtraction facts is needed here.) Word stories and recording for: 48 – 40, 51 – 20, 53 – 50, 27 – 20, 64 – 10, 43 – 40, 57 – 50, 71 - 40....
Using Number Properties
Examples. 97 – 10, 78 – 30, 20 + 62, 46 + 50, 80 + 17....
Challenging examples. The students will need to understand the meaning of three digit numbers to do these: 240 – 20, 340 – 40, 443 – 20, 570 - 20....