Exploring Times Tables Years 2 - 6

Summary Four children each turn over all the plugs in their yellow/blue board, then join their boards together to make an array of 100 plugs. With the help of two drinking straws they can find every Times Table they need to know inside the 10x10 array before them. Materials One Poly Plug each Two drinking straws (or pencils) Times Tables Plug Paper or Poly Plug Grid or maths journal Poly Plug Grid has many more plug images per page. It can be easily sliced into useful sections.

Note: This investigation has been included in Maths At Home. In this form it has fresh context and purpose and, in some cases, additional resources. Maths At Home activity plans encourage independent investigation through guided 'homework', or, for the teacher, can be an outline of a class investigation.

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Acknowledgement

Tony Harries, Durham University, saw something of our Rows & Straws in a workshop. He showed us how he uses 'slicers' in a neat piece of software based around 5x5 grids of circles. The synthesis of thoughts resulted in this activity.

Demonstrate how two straws are used at right angles on the four boards as shown in the picture above to 'fence in' some rows. The 'fence' is made from the two straws and the edges of the board. In the example above the children have fenced in four rows of six, or 4 x 6. The total is easy to count because the plugs on the left board are in rows of five. Clearly 4 x 6 = 4 x 5 + 4 = 24. Can you check it another way?

From The Classroom Ann Monkhouse and Alicia Ernst, St. Bede's Primary School, Braidwood, put the display below together to show how much their children learnt using Exploring Times Tables. The central panel in the photo shows significant additional learning that can develop using the activity. All four equations are clearly visible in the plug picture beside them. One of the nice things about Poly Plug is that the rows of ten are always visible, which encourages this extra learning. If we make, for example, 3 rows of 7 bottle tops, this 'complement to ten' is not present. Next Step As the students become more confident with the times tables and their connection with multiplication arrays invite them to try their own torture using the Number & Computation B Picture Puzzles menu. Partners need their own timing device. They choose which times tables they want to torture themselves with and the time between slides which suits them. They correct their own work and have to find two ways of knowing each answer.

Explore a few examples with the class, then invite them to use straws on their own boards to see what times tables they can find. Children take turns to place the straws and the whole group discusses what has been made. In this case the fence encloses 8 rows of 7. The top left board is automatically 25 and other parts add more counting by 5s or 10s; then there is only a small rectangle of 6 plugs (which look like a dice pattern). So... 8 x 7 = 25 + 3 x 5 + 5 x 2 + 6 = 56 Over time encourage students to transfer their learning to a drawing and hopefully a personal mental image and finally factual knowledge. Teachers find this Times Tables Plug Paper or Poly Plug Recording Grid at least as useful on the table top as a chart of times tables facts. Challenge the children further by turning over all the plugs to make the 10x10 tables and cover a section with a piece of card. How many plugs are covered? How do you know? Can you check it another way? (Thanks to Ulla Öberg, Malmö, Sweden for this insight.) Extensions With every 'fence in' there is a 'not fence in'. Use questions like: How many plugs are outside the fence? How many more plugs are needed to make a total of 100? Can you write an equation that equals 100 using your 'fenced' multiplication? and each of these is supported of course by the questions: How do you know? Can you check it another way? See the idea with the same name at the end of the Playing Cards activity, for an approach that gives this activity more of a co-operative game feel.

(Note: Picture Puzzles is built around one screen, two learners, concrete materials and a challenge and requires a separate membership.)

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