Times Market — Lesson 82a: Turn it around

What your child does, card by card

Turn it around. 4 × 3 and 3 × 4: the same? PlayType opens the lesson: “Times means groups of the same number.”

Watch me: 3, 8, 6, 9, 2 and 12 appear on the beads one move at a time, each bead ringed in green before it goes. Four groups of 3: 3, 6, 9, 12.

First a reminder (“3 × 4”): the beads build 4, 9, 8, 2 and 12, ring by ring, while your child watches. Three groups of 4: 4, 8, 12.

4 × 3 = 3 × 4: both make 12. The beads work the column line by line, zero, 4, 8 and 12, while the sum sheet below lights each line and ticks it; “4 × 3 = 12”, “3 × 4 = 12” and “The same!” light up as the total grows. Turn any times sum around: same answer.

In Try it a green ring marks the next bead while your child works out 2 × 5 and 5 × 2.

9 × 2 = 2 × 9: nine 2s is slow. Two 9s is quick! The beads work the column line by line, zero, 9 and 18, while the sum sheet below lights each line and ticks it; “9 × 2: nine steps”, “2 × 9: two steps” and “Both 18” light up as the total grows. Pick the way that is easier to count.

A tiny practice with no ring: work out 2 × 6, 5 × 3, 10 × 4, 3 × 5 and 4 × 10, each round starting from its own number.

Then the beads hide and the sums 2 × 7, 5 × 4 and 10 × 3 are done in the head, the answer picked from 14, 20 and 30.

You're ready! Turn a times sum around: the answer stays the same.

What this lesson trains

15 answers, roughly five minutes: 19 moves of the beads, 6 of them with the top bead and 13 with bottom beads. Numbers reach 40, so the tens rod and the ones rod work. Then 3 quick looks in your head. Friends do 3 of the 10 sums, by +5 = −5 +10, +2 = +5 −3 and +2 = −8 +10.

The first thing your child does: work out 2 × 5 and 5 × 2.

The sum sheet

In Column Tower the lower window is a sum sheet instead of the hands: the column written out one line under another, the line being worked in yellow, the lines done ticked, and the total once the last line is in. The beads keep the running total, so the abacus is never cleared in the middle of a column.

What PlayBuddy and PlayType say

PlayType: “Times means groups of the same number.”

PlayBuddy: “Four threes make twelve. Three fours make twelve too. Turn it around: same answer!”

Stars

With 1 or fewer slips across the 15 answers your child earns three stars; 3 or fewer, two.