The mental arithmetic shadow bead card refers to a picture of the abacus that the teacher assists the student in establishing the abacus image and assists the calculation when entering the mental arithmetic unit. It is the setting between the second and fourth column, upper one bead, lower four beads are the same as the physical abacus, but they are changed to flat paper. The shadow bead card is attached to many mental arithmetic textbooks. When it is cut out, it can be use for mental arithmetic homework. Students can use the thumb and index finger on the picture to find the answer according to the rules of the bead, to help the students.
The advantages of Shadow bead Card:
(1) Assist students who are just beginning to do mental arithmetic, establish images early and build self-confidence, especially for young students.
(2) Assist teachers in improving teaching quality. The use of the shadow bead card can assist teachers with less experience to solve the teaching process.
(3) It is portable and ready to use at any time, and can also be used in the mental arithmetic test.
Disadvantages of the shadow bead card:
(1) Students use it and became a habits, it may easily dependent on it. It could not be abandoned, and does not meet the true requirements of mental arithmetic.
(2) The pictures attached to some books are too large, and students use their design to move their fingers, which is slow and not finesse enough.
(3) Less digits, fewer rows and borrowing in a short time may achieve the effect of learning. Long-term use may hinder the progress of the later stage.
Whether the shadow bead card is used or not to use, it really depends on the individual, but also differs from person to person. A few suggestions are as follows:
(1) The timing of entering mental arithmetic should depend on whether the students are prepared enough. Since the formation of mental arithmetic images depends on whether the basis of abacus addition and subtraction is correct and skilled. With a moderate amount of practice, the image of the abacus has been formed in the brain, without the help of the shadow bead card.
(2) If the curriculum is properly arranged, before entering the mental arithmetic, it is suggested to start mental arithmetic with hearing first to let the teacher guide the students to the correct mental arithmetic method. It’s important to give the right method at the beginning, because it is difficult to adjust later.
you can't use the pen calculation directly;
you can't have the answer before you can move the beads;
you can't do the answer in stages.
The teacher first guides mindfulness calculations, requiring students to do the bead movements, develop correct postures and establish abacus images, and then enter to see mental calculations, students will proceed according to what they have learned.
(3) Of course, some students may have poor comprehension and proficiency. Even if they have sufficient abacus foundation, it is difficult to create images. It is possible to use the Shadow bead card for short-term assistance. Once you understand the operation method, you can discard it. Or ask the teacher to guide students to use mental arithmetic and abacus interchangeably. If the answer is correct, continue to use mental arithmetic to answer; if the answer is wrong, use abacus verification to enhance the image.
(4) If you still need to use the shadow bead card to assist teaching, the size of the picture must match or be smaller than the physical bead, in order to achieve the learning effect and not overly dependent.