Times Market — Lesson 81: Times: groups of the same number

What your child does, card by card

Times: groups of the same number. 3 × 4 means 3 groups of 4. PlayType opens the lesson: “There is a faster way to add the same number again and again.”

3 × 4 = 4 + 4 + 4: three groups of 4 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”, “+ 4 = 8” and “+ 4 = 12” light up as the total grows. Say it: three times four.

2, 4, 6, 8, 10: each step is one more group of 2. The beads work the column line by line, zero, 2, 4, 6, 8 and 10, while the sum sheet below lights each line and ticks it; “2”, “4”, “6”, “8” and “10” light up as the total grows. 5 groups of 2 make 10: 5 × 2 = 10.

10, 20, 30, 40, 50: groups of ten live on the tens rod. The beads work the column line by line, zero, 10, 20, 30, 40 and 50, while the sum sheet below lights each line and ticks it; “10”, “20”, “30”, “40” and “50” light up as the total grows. 5 groups of 10 make 50: 5 × 10 = 50.

5, 10, 15, 20, 25: the abacus makes 5, 10, 15, 10, 20 and 25 by itself, a green ring on each bead just before it moves, and the sum sheet below ticks each line. Plus 5: the top bead. Or the twins: top bead off, one ten on.

In Try it a green ring marks the next bead while your child works out 10 × 2 and 10 × 5.

The tiny practice drops the ring: work out 6 × 2, 3 × 5, 4 × 10, 9 × 2 and 5 × 5, each round starting from its own number.

In your head: the abacus is covered and your child works out 7 × 2, 4 × 5 and 3 × 10, picking each answer from 14, 20 and 30.

You're ready! Times means groups of the same number. You can count by 2, 5 and 10.

What this lesson trains

18 answers, roughly five minutes: 27 moves of the beads, 11 of them with the top bead and 16 with bottom beads. Up to 50, read and set from the left. Then 3 quick looks in your head. The friend rules here: +2 = +5 −3, +2 = −8 +10 and +5 = −5 +10, used in 5 of 15 sums.

It starts with doing: work out 10 × 2 and 10 × 5.

The sum sheet

The lower window shows the column as a child would write it on paper: one number under another, the current line in yellow, ticks on the lines done. The abacus carries the running total from line to line.

What PlayBuddy and PlayType say

PlayType: “There is a faster way to add the same number again and again.”

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

PlayType: “Two, four, six, eight, ten. Five twos make ten!”

PlayType: “Ten, twenty, thirty, forty. And the top bead is fifty!”

Stars

18 answers: 1 slip still gives three stars; up to 4, two stars. A number counts as a slip only when it stays wrong for a moment and is not on the way to the answer, so a child who moves beads one at a time is never marked down. After two slips on one task the green ring comes back.

About Times Market

Times Market is Level 7 of nine (grade 3 to 4): tables, 2 × 1 digit, 2 × 2 digit. In your head: times sums in your head.