Level One > Number and Algebra

Ten Sweets Per Packet

Keywords:

Achievement Objectives:

Achievement Objective: Use a range of counting, grouping, and equal-sharing strategies with whole numbers and fractions.

Achievement Objective: Know groupings with five, within ten, and with ten.

Specific Learning Outcomes:

Solve addition and subtraction problems with decade numbers by counting tens in their heads.

Recall the facts up to 10, and the teen facts.

Recall the number of 10s within decades and decades that add to 100.

Description of mathematics:

Number Framework Stages 3 and 4

Required Resource Materials:

An abacus (alternatively place value materials in bundles of ten).

Activity:

Using Materials

Problem: “There are 10 sweets in each packet. Miranda has three packets, and her
grandfather buys her two more packets. How many sweets does Miranda have
altogether?”
Discuss why you write, “3 packets (of 10) + 2 packets (of 10)”. Below this, record 30 + 20 on the board or modelling book. Model 30 by three rows of 10 on the abacus (or on the bundled or container materials). Ask the students how to model 20. Discuss why the answer is 50 and record 30 + 20 = 50 on the board or modelling book.
Examples: Word stories and recording for: 3 packets + 1 packet 5 packets – 1 packet 1 packet + 5 packets 60 – 20 80 + 10 50 – 40 ...

Using Imaging

Shielding: Problem: “A packet contains 10 sweets. If Edward has seven packets and
Andrew has one packet, how many sweets do they have altogether?”
Record, “7 packets of 10 + 1 packet of 10”, and, below this, 70 + 10 on the board or modelling book. Model 70 on the abacus out of sight of the students. Ask them what you have done. Model 10 more.
Record 70 + 10 = 80 on the board or modelling book.
Examples: 5 packets + 3 packets 5 packets – 1 packet 3 packets – 2 packets
10 + 50 30 + 20 ...
Imaging Only: Examples: Word stories and recording for: 5 packets + 4 packets
50 – 40 90 – 40 50 + 10 80 + 10 ...