Represent repeated addition and arrays as multiplication, and sharing and repeated subtraction (grouping) as division
Representing Multiplication - arrays and number lines
Represents multiplication using an array and by jumping on a number line. Great for developing an understanding of multiplication by partitioning.
This game is now part of the 'Calculations' collection, which includes the following 17 games and resources: Column Addition, Expanded Addition, Expanded Addition - Place Value Counters, Number Bonds(2), Addition - Digit Drag, Missing Symbols, Column Subtraction, Column Subtraction using Place Value Counters, Counting on to find difference on a beadstring, Multiplication Grid Method, Multiplication Written Method, Ratio and Scaling Numbers, Representing Multiplication, Division by Chunking Up, Division by Chunking Down, Formal Written Division - Round Up or Down?, Short Division Writen Formal Method.
The Calculations app is available on Google Play and the App Store.
View full screen in your browser. This ITP allows you to display up to 30 counters or shapes on the screen. You then select a number to be the divisor in a division calculation. A number line displays the number to be divided. As individual counters or shapes are clicked and dragged to form a group the size of the divisor, they change colour. Once a group equal to the divisor is selected, it ‘jumps’ to the number line. In this example 22 counters were chosen and the divisor set to 5. In the example shown below, 3 sets of 5 shapes have been selected and moved to the number line, which shows each group as a jump. Four more counters have been dragged together and the fifth is about to be selected. The answer to the division calculation is shown at the bottom of the screen. The ITP can be used to model division as grouping and to link this process to jumps on a number line. It can also introduce children to how remainders are recorded in the answer.
View full screen in your browser. This ITP sets up an empty grid into which you can place counters. Counters can be added singly, working from the first empty top left-hand corner cell, or in bulk clicking on a cell in the final row. As each column is completed it is numbered. The division calculation representing the number of highlighted counters divided by the number of rows can be revealed and hidden using the equals sign button. The answer appears when the equals sign in the calculation is clicked. Any remainder can also be shown as a fraction. In the example, below, there are 17 counters in a grid with 5 rows. Three columns are completed and there are 2 counters in the incomplete column. The displayed result will be:
17÷ 5 = 3r2 or 17÷ 5 = 3 2/5
Removing or highlighting extra counters will change the calculation displayed.
The ITP can be used to demonstrate division as grouping, and to develop children’s understanding of remainders and the notation for division. Keeping the number of counters fixed but changing the number of rows demonstrates the effect of changing the divisor in the calculation. Children can explore the effect different divisors has on the remainder and they can look for division calculations whose remainders satisfy particular properties.