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 Mental arithmetic Two Cuisenaire rods on a number line. Select the Cuisenaire rods by clicking on the above buttons. D1: Cuisenaire Rods with number lines. Useful for lots of mental arithmetic activities (also work on fractions and ratio). The on and off buttons. Top: horizontal or vertical Cuisenaire rods. Delete all the Cuisenaire rods, they can also be deleted individually by dragging to the bin. Turn the numbers on or off. Turn the grid on or off. Turn the horizontal number line on or off. The number lines can be dragged up or down, or left or right. Turn the vertical number line on or off. The buttons D2: Find the difference between two numbers Two numbers are shown on a number line. Drag the two numbers along the number line or click on 'change'. Select the numbers on the number line by clicking on the appropriate button. Coloured bars can be shown to indicate one way of working out the difference. Click on the button showing the coloured bars to hide or show them. Click on the zoom button to zoom in or out. The number line can be dragged from side to side when it is magnified. Click in the boxes to hide or show the numbers or difference. D3: Find the total of two numbers Same idea as above but shows the total of two numbers. 50 is the maximum size for each number. No zoom facility. What are the hidden numbers? Reveal a few numbers, the pupils have to identify some of the hidden ones. D4: 100-grid activities This number grid can be used to identify hidden numbers. Click on a square to reveal the number. Useful for addition and subtraction activities using a normal 100-grid or number sequence activities using a random grid. There are four types of number grid: 1 to 100, 1 in the top-left hand corner, 100 in the bottom-right. 100 to 1, 100 in the top-left hand corner, 1 in the bottom-right. A random grid starting with smallest number in the top-left. A random grid starting with highest number in the top-left. Mental arithmetic 'tests' each comprising ten questions on addition, subtraction, multiplication, division, place value, sequences, fractions, measures, time and money. D5: National Curriculum: level 3 'test 1' D6: National Curriculum: level 3 'test 2' : slightly more difficult A mental arithmetic 'test' comprising ten questions on addition and subtraction. D7: National Curriculum: level 3