Mix Mountain — Lesson 61: Mix practice: adding

What your child does, card by card

Mix practice: adding. Practice day! PlayBuddy opens the lesson: “Practice time. Let's get quicker and better.”

First a reminder (“8 + 6: one up, top bead off, ten on”): the beads build 8, 9, 4 and 14, ring by ring, while your child watches. 6 is 5 and 1. The 1 first, then the 5.

Try it: your child works out 7 + 6 and 6 + 7, with a green ring on the next bead to move.

Five in a row: a mission of 8 tasks with a count of right answers in a row, with the best kept. Your child must work out 5 + 6, 6 + 8, 7 + 7, 5 + 9, 3 + 4, 8 + 6, 6 + 5 and 15 + 8.

Copy me: the hand in the lower window shows 13, 14 and 23, one at a time, and your child makes the same number on the beads.

Then the beads hide and the sums 6 + 6, 7 + 8 and 5 + 5 are done in the head, the answer shown on the fingers.

You're ready! All the adding, with every friend.

What this lesson trains

16 answers in about five minutes. The tasks take 34 bead moves in all: 10 with a top bead and 24 with bottom beads. Numbers reach 23, so the tens rod and the ones rod work. Then 3 quick looks in your head. 10 of the 10 sums need a friend (“+6 = +1 −5 +10”, “+7 = +2 −5 +10”, “+8 = +3 −5 +10”, “+9 = +4 −5 +10”, “+4 = +5 −1” and “+5 = −5 +10”); the others use free beads.

It starts with doing: work out 7 + 6 and 6 + 7.

Fingers and hands

Below the abacus the drawn hands show zero and 3, 5, 6, 7, 8, 11, 13, 14, 15 and 23 here, finger for bead: the left hand counts the tens, the right hand the ones.

+4 on the fingers: the thumb opens and one finger closes (+5 −1).

+6 on the fingers: the right hand opens one finger and folds the thumb, then the left hand opens one more finger for the ten (+1 −5 +10). +7 on the fingers: the right hand opens 2 fingers and folds the thumb, then the left hand opens one more finger for the ten (+2 −5 +10). +8 on the fingers: the right hand opens 3 fingers and folds the thumb, then the left hand opens one more finger for the ten (+3 −5 +10). +9 on the fingers: the right hand opens 4 fingers and folds the thumb, then the left hand opens one more finger for the ten (+4 −5 +10). +5 on the fingers: the right hand lets 5 go and the left hand opens one more finger for the ten (−5 +10).

In Copy me the hand leads with 13, 14 and 23 and your child turns each into beads.

What PlayBuddy and PlayType say

PlayBuddy: “First try the beads. Then the small friend. Then the big friend.”

Stars

16 answers: 1 slip still gives three stars; up to 4, two stars.